Several people have inquired about the Daystate MK4iS with Heliboard I have posted in the classifieds. I've sent this document to a couple people who had questions, but decided to post it for anyone who might be interested.
Daystate MK4iS with Upgraded Electronics Board (Helliboard)
About the rifle:
Daystate MK4iS
Upgraded Electronics Board (Helliboard)
Overall Length with Airstream Moderator: 928mm (39 ins)
Barrel Length: 430 mm (17 ins)
Cylinder Capacity: 144 cc
Weight (unscoped): 3.4 kg (7.5 lbs)
Caliber: 0.22 (5.5 mm)
Loading: Via bolt (electronically cocked and fired)
Magazine: 10-Shot rotary magazines and a magnetic single-shot loading tray
Fill Pressure: Up to 230 BAR (3,335 psi)
Power: From 3 to 38.5 FPE
Trigger: Electronic release. Adjustable for weight and length of stage. A Rowan Engineering target trigger is installed
Safety: Manual, electronic rotary lever with key-switch isolator
Stock: ‘S’ Model – Walnut sporter.
Aesthetics: 9/10Stock: The shape of the stock is eye-catching. I like the unique shape of the stock. It looks like a hybrid of a traditional stock and a thumbhole stock.
The rifle has excellent balance and is easy to steady when shooting offhand. There is nice checkering with the Daystate name proudly written down the bottom of the rifle.
The checkering is a welcome touch to add security when holding the rifle off-hand. The area is also grooved to allow your fingers purchase when gripping the gun. At first, I didn’t like this groove because I thought it added unnecessary bulk to the rifle. I prefered the more streamlined look of the Regal XL. However, I have come to appreciate the grooves as a way to improve accuracy. While shooting from a bench, pulling down on the rifle with the left hand via the grooves noticeably improves the rifles precision.
The elevated comb creates a great cheek rest. Finding the correct eye relief through the scope is automatic and comfortable as it should be on any rifle. The cheek piece looks deceptively high in large part because of the sharp curve of the butt down and away from the cheek piece. The butt looks a little strange at first glance, but is shaped to fit perfectly into the pocket of my shoulder.
The butt pad is not adjustable, and that is fine with me. I don’t like adjustable butt pads. In my opinion, they look silly when adjusted. I want the butt of the rifle to fit comfortably in the pocket of my shoulder without adjustment. This one does. The butt has a recoil pad which seems odd since the rifle has no recoil. I guess it is there to make the gun look like a high caliber big game rifle, but the presence of the air cylinder below the barrel and the moderator on the end definitely give it away as an air rifle.. The pad is textured and does a good job of sticking to clothes and making the rifle feel secure when held to the shoulder. I’d rather the butt pad be more slender and shave a half-inch off the length of the gun. The stock is attached to the rest of the gun using one beefy 8mm allen head screw. Removing it couldn’t be more simple.
Grip: The stippling on the grip is very well done. It provides great purchase while looking good. Your thumb has three places it can rest while shooting; two up high behind the bolt and one around the side toward the trigger. The two high ones are very useful while bench shooting. I am able to press down on the rifle with my thumb while squeezing the trigger to make the rifle more stable. I was surprised to learn that this trick helped improve my shooting accuracy.
First Impressions (Fit): 2/10
When I first got the rifle there was a significant amount of play between the stock and the air cylinder. This caused the barrel to have a very noticeable wobble. Fortunately, the stock was extremely easy to remove and a few pieces of electrical tape placed along the inside of the stock solved the problem easily.
Once this was fixed, there was also the matter of the barrel shroud clanking against the inside of the barrel band. Slight bumps of the shroud caused it to make a noticeable and cheap sounding “clunk” against the band. I couldn’t stand the way the sound cheapened the feel of the rifle. The fix was easy enough as I simply removed the barrel band and lined the inside of it with more black electrical tape. The low fit score is justified by the need to modify both the inside of the stock and barrel band with electrical tape to make everything nice and snug.
Finally, there is the fill cap. It seems handy at first that the cap sits snugly over the fill valve. However, I have found that wiggling the cap loose can cause it to rub on the bottom of the barrel and ruin the gun’s excellent finish. I suspect a screw cap would be better.
First Impressions (Finish): 9/10
I love the grain and color of the stock. The dark streaks of the grain look very classy and are the first clue that this is a high-end rifle. All the chrome and blueing are well done. The rifle looks and feels like a much higher caliber rifle. Each piece is expertly finished and looks quality.
Function: Handling, Loading, Firing, Noise, Filling: 8/10
Handling: 5/10
The Mk4iS is not a heavy rifle. Nor is it long or unwieldy to pack around for hunting/pesting. It aims easily. Unfortunately for the MK4, however, I also own a Brocock Contour S6. Compared to the Brocock Contour, which can be fired with one hand like a pistol, everything seems relatively bulky and unwieldy. If the Brocock is the gold standard or 10/10, easy handling bullpups would fill the 7/10, 8/10 and 9/10 ranks. That leaves the Mk4is in the middle of the next class or a 5/10.
Loading: 8/10
My opinion of the magazines has changed from my first impression. Initially, I was certain that Daystate had a winner with the magazines. They are easier to load than the similar magazines made from other companies I’ve tried. There is no spring to fight when starting to load pellets. Simply drop a pellet in the magazine and rotate the magazine to the next hole. The magazine holds 10 pellets. I was also impressed with how smoothly the magazines are inserted and removed from the gun. The magazines and single shot tray all have small magnets with just the right amount of strength to hold the magazines in place yet make removal a dream. Inserting and removing them is such a smooth process that it makes inserting the magazine on most any other air rifle jarring in comparison. The whole process screams QUALITY. In addition, each magazine has a red dot on the side to mark the last pellet. It is nice to be able to take a quick glance at the side of the gun and find out whether or not you are out of pellets.
As good as the magazines are, I decided to dock the score a couple of points because I found that predator polymags are a tad too long to load in the magazine. Also, loading wadcutter pellets is a bit hit-and-miss. 9 out of 10 wadcutters feed from the magazine with no trouble, but 1 in 10 seems to jam. Both these problems can be solved by using the slick as snot single shot tray. The biggest knock I have found against the magazines is that the rifle’s precision is noticeably better when loading with the single shot tray. We are talking about a variation of only a quarter of an inch at 25 yards. This is probably no big deal while hunting, but would be a killer in a Field Target match or benchrest competition. I have found that I seldom if ever use the magazines anymore because I am always shooting to be as accurate as possible.
Firing: 9/10
Firing the gun first requires the electronic safety to be turn off. The safety acts much like a power switch and gives the vibe that you are turning the gun on. It is a little strange at first but I got used to it very quickly. I deducted a point because I’m not particularly fond of the looks of the large safety switch and corresponding large red dot maring the looks of the gun. Once the gun is turned on, The bolt cycles very smoothly because the whole process of is electronic. There is no spring to compress which makes pulling the bolt back almost effortless. The phrase smooth as butter comes to mind. The bolt itself is a shiny chrome knob that isn’t quite my cup of tea. I’m not a fan of shiny bits on any of my guns. I’d rather the bolt be black like the shroud or air cylinder.
Like all guns, a gentle squeeze of the trigger sends the pellet out the barrel. Unlike other guns, the trigger of the Mk4iS is electrical. Pulling the trigger activates an electrical switch that causes the gun to fire. There is a nice distinct first stage. The second stage is nice and crisp. I lightened the second stage of the trigger quite a bit to aid in target shooting accuracy. It breaks at 6.8 oz. The trigger is top notch.
Rowan Engineering target trigger: The target trigger’s main benefit is allowing the position of the trigger to be modified. The blade can be canted to the side so that it is ergonomically easier to squeeze without moving the rifle. The blade can be moved forward or backward as per shooter’s preference. Both the stock trigger and the target trigger allow first and second stage adjustments. I prefer the target triggers adjustability for target shooting. If using the rifle as a hunting rig, I’d tighten the second stage and give the advantage to the stock trigger.
One odd note about firing the gun. The gun does not need to be cocked to fire. Cycling the bolt action is only necessary to load a new pellet through the magazine. The gun will actually fire a burst of air every time the trigger is pulled if the gun is “on”. This is a potential safety issue that an owner of a rifle like this needs to be aware of.
Preferred Pellet:
I have shot over 25 different types of pellet through the gun at a variety of distances and conditions, and unsurprisingly, the JSB brand is the preferred pellet for this gun. I have discovered that my Mk4 prefers pellets with a 5.51 or 5.52 pellet head diameter. It also really dislikes the harder lead pellets such as those from H&N. Most of the H&N pellets were difficult to push into the barrel from the magazine. The copper coated Baracuda Power were so difficult to load that I was afraid I’d bend the loading pin when pushing them in. The best JSB pellets seem to depend on the velocity and roughly break down like this:
Up to 15 FPE best pellet is the 13.43 grain JSB wadcutters or RS.
From 15 to 24 FPE the best pellet is the 15.89 Jumbo.
Above 24 FPE the 18.13 gr. Jumbo heavies are best.
Electronic Regulation: 8/10
The adjustability afforded by the electronic regulation is what makes this rifle unique and is the main cause of my purchase of the rifle. For me, the most fun thing about shooting air rifles is getting to know them. It’s not unlike the first few dates with a pretty girl when everything is exciting and new. Before long, the excitement and novelty turns into droll routine. My eyes start to wander toward the hot new thing on the other end of the shooting range. I imagine myself holding and caressing her and all the exciting times I could have getting to know her. My “old” rifle just isn’t as appealing anymore and I end up buying a new one and starting the cycle over again. The heli-board electronics board of the MK4 iS allows me to shoot the gun at 12 distinct settings. Pellet velocity and power can be varied anywhere between a pathetic 3 FPE up to a whopping 38.5+ FPE with heavy pellets. I can adjust the power down to allow for a full day’s worth of plinking in one fill with a flat shot curve, or crank it up for some serious hunting power. I can dial it in to be competition eligible for both 12 FPE and 20 FPE class rules. I can experiment to my heart’s content in order to find the most accurate pellet at every velocity and distance imaginable. In short, just like in life, everyone likes a good looking gun, but looks aren’t everything. I think the adjustability of the rifle might just make it a rifle I keep forever. Why not an AirWolf, you ask? I can’t get over the looks of bottle guns. Frankly, the looks of a gun matters greatly to me.
The adjustability and electronic regulation sounds great in theory, but how about actual practice? The use of a solenoid to regulate the force behind each shot is a cool idea so I was very curious as to its effectiveness. To make a long story short, when compared to a traditional regulator the solenoid is superior at improving air efficiency, shot count, and easy adjustability. Shot consistency can meet or beat the performance of a traditional regulator if time is put in to find the correct pulse widths for each setting. If the pulse widths are off, a traditional regulator will be more consistent.
Adjustability: 10/10
The rifle comes with a digital readout that displays 6 pieces of information.
Pressure: The top three numbers are the most frequently used. I love the digital reading for the remaining air pressure in the cylinder. I have found the gauges on other air guns to be imprecise at best and inaccurate at worst. The digital display leaves no guess work and makes filling to the exact desired air pressure simple. It also makes estimating the efficiency of the rifle easy because I can see how exactly how many BAR of pressure is used for each shot.
Shots Remaining: This adjustable setting tells the shooter how many shots are left on the current fill before pressure drops too low for desired velocity. This value can be adjusted to reflect any changes you make to individual power settings.
Power Level: Simply tells which Power setting the rifle is currently set to.
Capacitor Voltage: This value can be adjusted in the rifle menu to adjust the power of all power levels simultaneously. In order to get the most power out of the rifle, capacitor voltage would need to be raised. It can be adjusted up to 76 volts. The maker of the board says that shooting the rifle at higher voltages will shorten the life of the capacitor. Each 0.5 rise in voltage equates to about 10fps of increased velocity across all Power settings. I chose to set the rifle to 72.0 volts and remap each power setting curve to match my new voltage.
In addition to adjusting the voltage to increase or decrease the power of all settings to the gun, each setting can be adjusted up or down individually as well. For example, if I wanted to drop setting 4 from 12.2 FPE down to just under 12, I could change the power ratio for setting 4 from 1.00 down to .97 and thus reduce the power by about 3%. Each setting can be adjusted independent of the other settings this way.
The solenoid is very good at adjusting the power immediately after adjustment. For example, I can take a dozen shots at over 800 fps and 27 FPE on the 8 Power setting and then switch down to Power 3. The solenoid will immediately give consistent shots that are around 540 FPS and 12 FPE. The adjustability is all I dreamed it would be. It is very easy to change between power settings. Once each power setting is setup to your liking, it is the quickest way to adjust the power. I enjoyed customizing the settings to my individual needs.
Extra Info: This number tells how long the “pulse width” was for the last shot. The rifle reads the pressure in the air cylinder and sends a short burst of current to a solenoid. The longer the electrical burst, the longer the “pulse width” and the harder the hammer hits the air cylinder valve. The actual number for the pulse width usually decreases with each shot. This is because as the pressure inside the reservoir decreases, the hammer needs less force to open it. This pulse width number is how the rifles power adjustment is customized for each power setting.
Battery Voltage: Reading of how much charge there is in the battery. The rifle needs charged monthly. This is a pain-in-the-butt as I can see myself forgetting to charge the rifle for a few months of inuse over winter and having the battery go bad. I’ve also experienced a “Low Battery” message after a couple days of heavy shooting in a row. On the plus side, if the battery ever needs to be replaced, it is easy to access.
Efficiency and Shot Count: 10/10
Data collected using unsorted 15.89 grain JSB Exact Jumbo Pellets
Consistency: 8/10
The manual for the Helliboard states that the settings may need to be tweaked since each rifle, pellet weight and need of shooter is different. I found this to be 100% true. Better values can be determined while shooting shot strings and making note of the pressure and velocity of each shot. I recalibrated with these new and improved values to flatten out and customize each shot string. I calibrated each power setting to my own power specification and pellet weights. Each shot curve is now flat and consistent for each setting.
The 36 shot string (shown below) resulted in a standard deviation of 3.36 fps with an extreme spread of 18 fps. The electronic regulation has a habit of letting an occasional shot shoot hotter or slower than the rest of the string (thus keeping the consistency score from being perfect). In this sample, shot 22 was a little hotter than the rest and ruined an otherwise stellar shot string. The biggest issue I have found with the electronic regulation of the Daystate and Helliboard are these occasional blips in velocity. I am not certain what causes 1% to 2% of the shots to be “fliers”. I suspect the answer is that the Helliboard is checking and adjusting the pressure inside the reservoir about twice per second. After each shot, the remaining volume of air in the reservoir is agitated and can fluctuate up to a BAR of pressure before it settles back down. The solenoid relies on an accurate reservoir pressure to determine how hard to strike the hammer. I think the fluctuations of pressure immediately after a shot lead to the occasional hot or cold shot. The rate of these “fliers” does seem to be correlated with rapid firing of the gun. Without these fliers, the consistency would be outstanding. These fliers are the sole reason I docked 2 points for consistency. They don’t result in a different POI at high velocities or short distances. However, they are definitely noticeable out to 100+ yards and slower velocities.
Noise: 9/10
To keep the gun quiet, Daystate has given the barrel a full shroud as well as attached an in-house moderator to the end. The moderator is an Airstream Mk5. It is about 6 inches long. It keeps the length of the barrel a reasonable length by fitting over the shrouded barrel for about 4 inches so that only two additional inches is added to the length. The Airstream is wrapped in carbon fiber and at first glance is the most obvious sign that the gun is an air rifle (The second being the air cylinder hiding under the barrel shroud). Without the moderator or cylinder, the thick shrouded barrel would convince the casual looker that the gun is a high caliber hunting rifle.
So what does firing the gun sound like? I have put a lot of thought into trying to accurately describe the sound of the gun firing. Adding to the difficulty, the gun’s power output is so adjustable that the sound output is highly adjustable, too. The best I can come up with is that the gun sounds like a stapler being squeezed to staple two pieces of paper together. At the lower settings, the rifle sounds like a person trying to quietly staple papers together. There is a perceptible click sound. As the power is turned up the loudness of the stapler sound rises correspondingly. At power 12 a shot fired sounds like a person dropping their fist onto the stapler. The sound is definitely backyard friendly at the lower settings. I do most of my backyard shooting at settings between 12 and 18 FPE. I imagine that if my neighbors even notice the sound at all that they think I am sitting on my porch stapling papers together.
Refill: 10/10
The Daystate can be filled all the way up to 230 BAR (3335 psi). The fill cap is easily removed from the end of the air cylinder to expose a standard male fitting. The hose on my air tank came equipped with a female quick connect that makes filling the rifle easy. Many air gun manufacturers require a specialized fill probe to fill their guns. I appreciate that Daystate has avoided the requirement of a fill probe and gone with the most simple method of filling. Both my Brocock Contour and my Daystate can be filled using the same hose connection. The digital pressure gauge on the side of the rifle is extremely accurate. I like being able to keep track of air pressure while filing and shooting to the nearest BAR.
Summary and Overall impression: 9/10
If forced to own only one air gun, the MK4iS with upgraded electronics board would be it. I have summarized the pros and cons I have found thus far for the rifle below. Since most of the cons were easily fixed, my overall ranking score for the Daystate MK4iS is 9/10.
Pro:
Daystate MK4iS with Upgraded Electronics Board (Helliboard)
About the rifle:
Daystate MK4iS
Upgraded Electronics Board (Helliboard)
Overall Length with Airstream Moderator: 928mm (39 ins)
Barrel Length: 430 mm (17 ins)
Cylinder Capacity: 144 cc
Weight (unscoped): 3.4 kg (7.5 lbs)
Caliber: 0.22 (5.5 mm)
Loading: Via bolt (electronically cocked and fired)
Magazine: 10-Shot rotary magazines and a magnetic single-shot loading tray
Fill Pressure: Up to 230 BAR (3,335 psi)
Power: From 3 to 38.5 FPE
Trigger: Electronic release. Adjustable for weight and length of stage. A Rowan Engineering target trigger is installed
Safety: Manual, electronic rotary lever with key-switch isolator
Stock: ‘S’ Model – Walnut sporter.
Aesthetics: 9/10Stock: The shape of the stock is eye-catching. I like the unique shape of the stock. It looks like a hybrid of a traditional stock and a thumbhole stock.
The rifle has excellent balance and is easy to steady when shooting offhand. There is nice checkering with the Daystate name proudly written down the bottom of the rifle.
The checkering is a welcome touch to add security when holding the rifle off-hand. The area is also grooved to allow your fingers purchase when gripping the gun. At first, I didn’t like this groove because I thought it added unnecessary bulk to the rifle. I prefered the more streamlined look of the Regal XL. However, I have come to appreciate the grooves as a way to improve accuracy. While shooting from a bench, pulling down on the rifle with the left hand via the grooves noticeably improves the rifles precision.
The elevated comb creates a great cheek rest. Finding the correct eye relief through the scope is automatic and comfortable as it should be on any rifle. The cheek piece looks deceptively high in large part because of the sharp curve of the butt down and away from the cheek piece. The butt looks a little strange at first glance, but is shaped to fit perfectly into the pocket of my shoulder.
The butt pad is not adjustable, and that is fine with me. I don’t like adjustable butt pads. In my opinion, they look silly when adjusted. I want the butt of the rifle to fit comfortably in the pocket of my shoulder without adjustment. This one does. The butt has a recoil pad which seems odd since the rifle has no recoil. I guess it is there to make the gun look like a high caliber big game rifle, but the presence of the air cylinder below the barrel and the moderator on the end definitely give it away as an air rifle.. The pad is textured and does a good job of sticking to clothes and making the rifle feel secure when held to the shoulder. I’d rather the butt pad be more slender and shave a half-inch off the length of the gun. The stock is attached to the rest of the gun using one beefy 8mm allen head screw. Removing it couldn’t be more simple.
Grip: The stippling on the grip is very well done. It provides great purchase while looking good. Your thumb has three places it can rest while shooting; two up high behind the bolt and one around the side toward the trigger. The two high ones are very useful while bench shooting. I am able to press down on the rifle with my thumb while squeezing the trigger to make the rifle more stable. I was surprised to learn that this trick helped improve my shooting accuracy.
First Impressions (Fit): 2/10
When I first got the rifle there was a significant amount of play between the stock and the air cylinder. This caused the barrel to have a very noticeable wobble. Fortunately, the stock was extremely easy to remove and a few pieces of electrical tape placed along the inside of the stock solved the problem easily.
Once this was fixed, there was also the matter of the barrel shroud clanking against the inside of the barrel band. Slight bumps of the shroud caused it to make a noticeable and cheap sounding “clunk” against the band. I couldn’t stand the way the sound cheapened the feel of the rifle. The fix was easy enough as I simply removed the barrel band and lined the inside of it with more black electrical tape. The low fit score is justified by the need to modify both the inside of the stock and barrel band with electrical tape to make everything nice and snug.
Finally, there is the fill cap. It seems handy at first that the cap sits snugly over the fill valve. However, I have found that wiggling the cap loose can cause it to rub on the bottom of the barrel and ruin the gun’s excellent finish. I suspect a screw cap would be better.
First Impressions (Finish): 9/10
I love the grain and color of the stock. The dark streaks of the grain look very classy and are the first clue that this is a high-end rifle. All the chrome and blueing are well done. The rifle looks and feels like a much higher caliber rifle. Each piece is expertly finished and looks quality.
Function: Handling, Loading, Firing, Noise, Filling: 8/10
Handling: 5/10
The Mk4iS is not a heavy rifle. Nor is it long or unwieldy to pack around for hunting/pesting. It aims easily. Unfortunately for the MK4, however, I also own a Brocock Contour S6. Compared to the Brocock Contour, which can be fired with one hand like a pistol, everything seems relatively bulky and unwieldy. If the Brocock is the gold standard or 10/10, easy handling bullpups would fill the 7/10, 8/10 and 9/10 ranks. That leaves the Mk4is in the middle of the next class or a 5/10.
Loading: 8/10
My opinion of the magazines has changed from my first impression. Initially, I was certain that Daystate had a winner with the magazines. They are easier to load than the similar magazines made from other companies I’ve tried. There is no spring to fight when starting to load pellets. Simply drop a pellet in the magazine and rotate the magazine to the next hole. The magazine holds 10 pellets. I was also impressed with how smoothly the magazines are inserted and removed from the gun. The magazines and single shot tray all have small magnets with just the right amount of strength to hold the magazines in place yet make removal a dream. Inserting and removing them is such a smooth process that it makes inserting the magazine on most any other air rifle jarring in comparison. The whole process screams QUALITY. In addition, each magazine has a red dot on the side to mark the last pellet. It is nice to be able to take a quick glance at the side of the gun and find out whether or not you are out of pellets.
As good as the magazines are, I decided to dock the score a couple of points because I found that predator polymags are a tad too long to load in the magazine. Also, loading wadcutter pellets is a bit hit-and-miss. 9 out of 10 wadcutters feed from the magazine with no trouble, but 1 in 10 seems to jam. Both these problems can be solved by using the slick as snot single shot tray. The biggest knock I have found against the magazines is that the rifle’s precision is noticeably better when loading with the single shot tray. We are talking about a variation of only a quarter of an inch at 25 yards. This is probably no big deal while hunting, but would be a killer in a Field Target match or benchrest competition. I have found that I seldom if ever use the magazines anymore because I am always shooting to be as accurate as possible.
Firing: 9/10
Firing the gun first requires the electronic safety to be turn off. The safety acts much like a power switch and gives the vibe that you are turning the gun on. It is a little strange at first but I got used to it very quickly. I deducted a point because I’m not particularly fond of the looks of the large safety switch and corresponding large red dot maring the looks of the gun. Once the gun is turned on, The bolt cycles very smoothly because the whole process of is electronic. There is no spring to compress which makes pulling the bolt back almost effortless. The phrase smooth as butter comes to mind. The bolt itself is a shiny chrome knob that isn’t quite my cup of tea. I’m not a fan of shiny bits on any of my guns. I’d rather the bolt be black like the shroud or air cylinder.
Like all guns, a gentle squeeze of the trigger sends the pellet out the barrel. Unlike other guns, the trigger of the Mk4iS is electrical. Pulling the trigger activates an electrical switch that causes the gun to fire. There is a nice distinct first stage. The second stage is nice and crisp. I lightened the second stage of the trigger quite a bit to aid in target shooting accuracy. It breaks at 6.8 oz. The trigger is top notch.
Rowan Engineering target trigger: The target trigger’s main benefit is allowing the position of the trigger to be modified. The blade can be canted to the side so that it is ergonomically easier to squeeze without moving the rifle. The blade can be moved forward or backward as per shooter’s preference. Both the stock trigger and the target trigger allow first and second stage adjustments. I prefer the target triggers adjustability for target shooting. If using the rifle as a hunting rig, I’d tighten the second stage and give the advantage to the stock trigger.
One odd note about firing the gun. The gun does not need to be cocked to fire. Cycling the bolt action is only necessary to load a new pellet through the magazine. The gun will actually fire a burst of air every time the trigger is pulled if the gun is “on”. This is a potential safety issue that an owner of a rifle like this needs to be aware of.
Preferred Pellet:
I have shot over 25 different types of pellet through the gun at a variety of distances and conditions, and unsurprisingly, the JSB brand is the preferred pellet for this gun. I have discovered that my Mk4 prefers pellets with a 5.51 or 5.52 pellet head diameter. It also really dislikes the harder lead pellets such as those from H&N. Most of the H&N pellets were difficult to push into the barrel from the magazine. The copper coated Baracuda Power were so difficult to load that I was afraid I’d bend the loading pin when pushing them in. The best JSB pellets seem to depend on the velocity and roughly break down like this:
Up to 15 FPE best pellet is the 13.43 grain JSB wadcutters or RS.
From 15 to 24 FPE the best pellet is the 15.89 Jumbo.
Above 24 FPE the 18.13 gr. Jumbo heavies are best.
Electronic Regulation: 8/10
The adjustability afforded by the electronic regulation is what makes this rifle unique and is the main cause of my purchase of the rifle. For me, the most fun thing about shooting air rifles is getting to know them. It’s not unlike the first few dates with a pretty girl when everything is exciting and new. Before long, the excitement and novelty turns into droll routine. My eyes start to wander toward the hot new thing on the other end of the shooting range. I imagine myself holding and caressing her and all the exciting times I could have getting to know her. My “old” rifle just isn’t as appealing anymore and I end up buying a new one and starting the cycle over again. The heli-board electronics board of the MK4 iS allows me to shoot the gun at 12 distinct settings. Pellet velocity and power can be varied anywhere between a pathetic 3 FPE up to a whopping 38.5+ FPE with heavy pellets. I can adjust the power down to allow for a full day’s worth of plinking in one fill with a flat shot curve, or crank it up for some serious hunting power. I can dial it in to be competition eligible for both 12 FPE and 20 FPE class rules. I can experiment to my heart’s content in order to find the most accurate pellet at every velocity and distance imaginable. In short, just like in life, everyone likes a good looking gun, but looks aren’t everything. I think the adjustability of the rifle might just make it a rifle I keep forever. Why not an AirWolf, you ask? I can’t get over the looks of bottle guns. Frankly, the looks of a gun matters greatly to me.
The adjustability and electronic regulation sounds great in theory, but how about actual practice? The use of a solenoid to regulate the force behind each shot is a cool idea so I was very curious as to its effectiveness. To make a long story short, when compared to a traditional regulator the solenoid is superior at improving air efficiency, shot count, and easy adjustability. Shot consistency can meet or beat the performance of a traditional regulator if time is put in to find the correct pulse widths for each setting. If the pulse widths are off, a traditional regulator will be more consistent.
Adjustability: 10/10
The rifle comes with a digital readout that displays 6 pieces of information.
Pressure: The top three numbers are the most frequently used. I love the digital reading for the remaining air pressure in the cylinder. I have found the gauges on other air guns to be imprecise at best and inaccurate at worst. The digital display leaves no guess work and makes filling to the exact desired air pressure simple. It also makes estimating the efficiency of the rifle easy because I can see how exactly how many BAR of pressure is used for each shot.
Shots Remaining: This adjustable setting tells the shooter how many shots are left on the current fill before pressure drops too low for desired velocity. This value can be adjusted to reflect any changes you make to individual power settings.
Power Level: Simply tells which Power setting the rifle is currently set to.
Capacitor Voltage: This value can be adjusted in the rifle menu to adjust the power of all power levels simultaneously. In order to get the most power out of the rifle, capacitor voltage would need to be raised. It can be adjusted up to 76 volts. The maker of the board says that shooting the rifle at higher voltages will shorten the life of the capacitor. Each 0.5 rise in voltage equates to about 10fps of increased velocity across all Power settings. I chose to set the rifle to 72.0 volts and remap each power setting curve to match my new voltage.
In addition to adjusting the voltage to increase or decrease the power of all settings to the gun, each setting can be adjusted up or down individually as well. For example, if I wanted to drop setting 4 from 12.2 FPE down to just under 12, I could change the power ratio for setting 4 from 1.00 down to .97 and thus reduce the power by about 3%. Each setting can be adjusted independent of the other settings this way.
The solenoid is very good at adjusting the power immediately after adjustment. For example, I can take a dozen shots at over 800 fps and 27 FPE on the 8 Power setting and then switch down to Power 3. The solenoid will immediately give consistent shots that are around 540 FPS and 12 FPE. The adjustability is all I dreamed it would be. It is very easy to change between power settings. Once each power setting is setup to your liking, it is the quickest way to adjust the power. I enjoyed customizing the settings to my individual needs.
Extra Info: This number tells how long the “pulse width” was for the last shot. The rifle reads the pressure in the air cylinder and sends a short burst of current to a solenoid. The longer the electrical burst, the longer the “pulse width” and the harder the hammer hits the air cylinder valve. The actual number for the pulse width usually decreases with each shot. This is because as the pressure inside the reservoir decreases, the hammer needs less force to open it. This pulse width number is how the rifles power adjustment is customized for each power setting.
Battery Voltage: Reading of how much charge there is in the battery. The rifle needs charged monthly. This is a pain-in-the-butt as I can see myself forgetting to charge the rifle for a few months of inuse over winter and having the battery go bad. I’ve also experienced a “Low Battery” message after a couple days of heavy shooting in a row. On the plus side, if the battery ever needs to be replaced, it is easy to access.
Efficiency and Shot Count: 10/10
Data collected using unsorted 15.89 grain JSB Exact Jumbo Pellets
Consistency: 8/10
The manual for the Helliboard states that the settings may need to be tweaked since each rifle, pellet weight and need of shooter is different. I found this to be 100% true. Better values can be determined while shooting shot strings and making note of the pressure and velocity of each shot. I recalibrated with these new and improved values to flatten out and customize each shot string. I calibrated each power setting to my own power specification and pellet weights. Each shot curve is now flat and consistent for each setting.
The 36 shot string (shown below) resulted in a standard deviation of 3.36 fps with an extreme spread of 18 fps. The electronic regulation has a habit of letting an occasional shot shoot hotter or slower than the rest of the string (thus keeping the consistency score from being perfect). In this sample, shot 22 was a little hotter than the rest and ruined an otherwise stellar shot string. The biggest issue I have found with the electronic regulation of the Daystate and Helliboard are these occasional blips in velocity. I am not certain what causes 1% to 2% of the shots to be “fliers”. I suspect the answer is that the Helliboard is checking and adjusting the pressure inside the reservoir about twice per second. After each shot, the remaining volume of air in the reservoir is agitated and can fluctuate up to a BAR of pressure before it settles back down. The solenoid relies on an accurate reservoir pressure to determine how hard to strike the hammer. I think the fluctuations of pressure immediately after a shot lead to the occasional hot or cold shot. The rate of these “fliers” does seem to be correlated with rapid firing of the gun. Without these fliers, the consistency would be outstanding. These fliers are the sole reason I docked 2 points for consistency. They don’t result in a different POI at high velocities or short distances. However, they are definitely noticeable out to 100+ yards and slower velocities.
Noise: 9/10
To keep the gun quiet, Daystate has given the barrel a full shroud as well as attached an in-house moderator to the end. The moderator is an Airstream Mk5. It is about 6 inches long. It keeps the length of the barrel a reasonable length by fitting over the shrouded barrel for about 4 inches so that only two additional inches is added to the length. The Airstream is wrapped in carbon fiber and at first glance is the most obvious sign that the gun is an air rifle (The second being the air cylinder hiding under the barrel shroud). Without the moderator or cylinder, the thick shrouded barrel would convince the casual looker that the gun is a high caliber hunting rifle.
So what does firing the gun sound like? I have put a lot of thought into trying to accurately describe the sound of the gun firing. Adding to the difficulty, the gun’s power output is so adjustable that the sound output is highly adjustable, too. The best I can come up with is that the gun sounds like a stapler being squeezed to staple two pieces of paper together. At the lower settings, the rifle sounds like a person trying to quietly staple papers together. There is a perceptible click sound. As the power is turned up the loudness of the stapler sound rises correspondingly. At power 12 a shot fired sounds like a person dropping their fist onto the stapler. The sound is definitely backyard friendly at the lower settings. I do most of my backyard shooting at settings between 12 and 18 FPE. I imagine that if my neighbors even notice the sound at all that they think I am sitting on my porch stapling papers together.
Refill: 10/10
The Daystate can be filled all the way up to 230 BAR (3335 psi). The fill cap is easily removed from the end of the air cylinder to expose a standard male fitting. The hose on my air tank came equipped with a female quick connect that makes filling the rifle easy. Many air gun manufacturers require a specialized fill probe to fill their guns. I appreciate that Daystate has avoided the requirement of a fill probe and gone with the most simple method of filling. Both my Brocock Contour and my Daystate can be filled using the same hose connection. The digital pressure gauge on the side of the rifle is extremely accurate. I like being able to keep track of air pressure while filing and shooting to the nearest BAR.
Summary and Overall impression: 9/10
If forced to own only one air gun, the MK4iS with upgraded electronics board would be it. I have summarized the pros and cons I have found thus far for the rifle below. Since most of the cons were easily fixed, my overall ranking score for the Daystate MK4iS is 9/10.
Pro:
- Infinite adjustability
- Very quiet at low settings
- Near unlimited shot count at low settings
- Very powerful at high settings
- Accurate - especially with single shot tray
- Beautiful gun
- Excellent magazines
- Comfortable shooter
- Easy to fill
- Required use of electrical tape to better fit air reservoir into the stock and shroud into barrel band.
- Battery requires charging each month.
- You love to tinker with rifle settings and fine tune for power and accuracy.
- You want a gun that you won’t get bored with.
- You want to do some quiet pesting in the backyard.
- You like to target shoot out to 100+ yards with accuracy.
- You like to plink hundreds of shots without needing to refill.
- The thought of reprogramming the power settings scares you. The adjustability is the huge draw of the rifle.
- You are a doomsday prepper. The electronics on this gun need charged once a month.
