Skout Everything Skout EVO and Epoch
- Thread starter MSR Workshop
- Start date
Well, I suppose it’s time to report back on my latest tinkering experiment.
I completely disassembled the high-pressure regulator, and you’ll notice there are concentric holes around two parts of the lower section of the regulator. I decided to enlarge every one of those holes to 3 mm. I also took the poppet valve (or needle valve—whatever you want to call it) and enlarged its orifice to 1 mm.
My thinking was that if I completely messed it up, I’d just chalk it up to science—it’s a replaceable part, after all. But so far, I can report that the gun has been performing quite nicely. The recovery time on my digital gauge seems a little quicker, and my extreme spread has tightened up as well. I’ve also noticed the low-pressure regulator seems a bit more sensitive to tuning now—although that could just be my imagination.
The idea behind this modification was to reduce any restriction in the path to the spool valve, helping it recover more quickly between shots.
I’ve included a picture of the needle valve I enlarged, as well as a stock photo of the high-pressure regulator with the holes I’m referring to.
Happy shooting, everyone!
I completely disassembled the high-pressure regulator, and you’ll notice there are concentric holes around two parts of the lower section of the regulator. I decided to enlarge every one of those holes to 3 mm. I also took the poppet valve (or needle valve—whatever you want to call it) and enlarged its orifice to 1 mm.
My thinking was that if I completely messed it up, I’d just chalk it up to science—it’s a replaceable part, after all. But so far, I can report that the gun has been performing quite nicely. The recovery time on my digital gauge seems a little quicker, and my extreme spread has tightened up as well. I’ve also noticed the low-pressure regulator seems a bit more sensitive to tuning now—although that could just be my imagination.
The idea behind this modification was to reduce any restriction in the path to the spool valve, helping it recover more quickly between shots.
I’ve included a picture of the needle valve I enlarged, as well as a stock photo of the high-pressure regulator with the holes I’m referring to.
Happy shooting, everyone!
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Interesting, can't really comment either ways as to my thinking at the sorts of pressures used I am not sure how much flow comes into it, but it must for some of the aperture modifications made to have an observable effect, I too opened out the poppet aperture to 1mm, and I have noticed a decrease in shot to shot air use but nothing else, and will be getting another poppet so I can experiment further with a larger aperture, which also says that the size of the hole does matter, and while I used to know my airflow characteristics when tuning cars I am, not sure about the high pressure stuff, but its people like us who are prepared to take the risk and try this stuff that make gun tuning interesting, so well done for being adventurous.
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HaInteresting, can't really comment either ways as to my thinking at the sorts of pressures used I am not sure how much flow comes into it, but it must for some of the aperture modifications made to have an observable effect, I too opened out the poppet aperture to 1mm, and I have noticed a decrease in shot to shot air use but nothing else, and will be getting another poppet so I can experiment further with a larger aperture, which also says that the size of the hole does matter, and while I used to know my airflow characteristics when tuning cars I am, not sure about the high pressure stuff, but its people like us who are prepared to take the risk and try this stuff that make gun tuning interesting, so well done for being adventurous.
Thanks.
I wouldn’t know how wide to open that poppet just for fear of weakening the sides of the metal because so much force has applied onto it with that regulator spring pushing against from that piston.
I had one that I had replaced because it was ever so slightly bent.
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One thing to remember when dealing with small parts in relation to HPA is that you're dealing with much less stress due to the size, so not being good at maths if you're working with 2-3,000psi it's much reduced when confined to 0.050" .Ha
Thanks.
I wouldn’t know how wide to open that poppet just for fear of weakening the sides of the metal because so much force has applied onto it with that regulator spring pushing against from that piston.
I had one that I had replaced because it was ever so slightly bent.
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Interesting observation on my further testing of the Epoch, after seeing the position of @Ada s FX chrono I decided to get mine as far back as possible on the barrel shroud so not quite on the M LOC rail but close, and the result was much more stable readings and gave a 10fps spread over 36 pellets with a 2.1 average, and further testing with different pellets gave similar readings.
Another thing I also kept track of since enlarging the hole in the poppet valve was the use of air was much better with readings of just 15-18bar for 36 pellets, which is very good, but you have to remember that this is sub 12, so velocities are around to 780fps mark, but it still results in about 1/2 a bar per pellet and most strive to get it at bar per pellet so pretty pleased with these results.
Another thing I also kept track of since enlarging the hole in the poppet valve was the use of air was much better with readings of just 15-18bar for 36 pellets, which is very good, but you have to remember that this is sub 12, so velocities are around to 780fps mark, but it still results in about 1/2 a bar per pellet and most strive to get it at bar per pellet so pretty pleased with these results.
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Is that FX chrono mounted to the mlok rail directly? And if so do you by any chance have a print file for it?
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Hi, yes it is mounted on an mlok picatini rail.
Here is a download link for the stl , you might need to slightly adjust the size depending on your printer.
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Well, I decided to drill out the needle valve to 1mm and the high-pressure regulator body holes to 2.5mm on my scout Epoch as well and it worked fantastic as well.
My extreme spread is now six point 6.6 over 33 shots. I also took no test shots prior to reinstalling the regulator and I just guessed at how far to screw it in and it actually came out perfect
Pre-drilling was 10.2 and that’s after deleting one shot.
My extreme spread is now six point 6.6 over 33 shots. I also took no test shots prior to reinstalling the regulator and I just guessed at how far to screw it in and it actually came out perfect
Pre-drilling was 10.2 and that’s after deleting one shot.
As an Epoch owner, I’m so grateful for this sort of research and modification info. I am looking to better understand the relationship between HP and LP reg settings and how they affect velocity, ES, and SD. Any experts out there?
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The low-pressure (LP) regulator on the Skout EVO airgun controls the air used to operate the rifle’s pneumatic cycling mechanisms—essentially managing the spool valve that releases air to propel the pellet. This is different from the high-pressure (HP) regulator, which governs the air pressure directly behind the projectile. The two regulators work in relation to one another, and fine-tuning both is key to proper cycling and overall performance.
Because the EVO platform is still relatively new, there isn’t an official manual that specifies what each pressure setting does. Part of the reason is the near-infinite variability in tuning. My own testing is still in the early stages, especially since I’ve been experimenting with modifications to the HP regulator and transfer port.
Before the modifications, the LP regulator didn’t seem to make a huge difference, but I did notice that turning it up resulted in a more forceful spool valve cycle and slightly tighter groups. Since then, I’ve made several changes: I enlarged the transfer port seat on my .177, modified the needle valve inside the HP regulator body, and refined the overall airflow path. These adjustments have allowed me to run both regulators at significantly lower pressures—while actually improving results.
Performance Comparison:
- Pre-modification:
• Pellet: 13.43 grain, .177 caliber
• Velocity: ~800 fps
• HP regulator: ~2000–2200 psi
• LP regulator: ~200 psi
• Accuracy: Good, but not outstanding - Post-modification:
• Pellet: 13.43 grain, .177 caliber
• Velocity: ~820 fps
• HP regulator: ~1000 psi
• LP regulator: ~100 psi
• Accuracy: Exceptionally tight groups—often same-hole shots
Finally, on the dwell setting: I’ve kept it as low as possible while still allowing the spool valve to open. If the dwell is set too low, the valve won’t open; set it too high, and it won’t close correctly. Striking the right balance is essential.
unfortunately, the dwell setting is not exactly like increasing or decreasing a hammer spring where you’ll see a 2-3-4-5-6 ft./s increase. Maybe just an ever so slight tightening of groups.
Hope this helps more than it adds to any confusion.
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Thanks! This is very insightful indeed in terms of LPR playing a larger role in the EVO, would this also apply or the EPOCH. Not sure if relevant but just received the high power kit for EPOCH which I have not yet installed. I have an older HP reg I may try to modify as you describe with larger openingsThe low-pressure (LP) regulator on the Skout EVO airgun controls the air used to operate the rifle’s pneumatic cycling mechanisms—essentially managing the spool valve that releases air to propel the pellet. This is different from the high-pressure (HP) regulator, which governs the air pressure directly behind the projectile. The two regulators work in relation to one another, and fine-tuning both is key to proper cycling and overall performance.
Because the EVO platform is still relatively new, there isn’t an official manual that specifies what each pressure setting does. Part of the reason is the near-infinite variability in tuning. My own testing is still in the early stages, especially since I’ve been experimenting with modifications to the HP regulator and transfer port.
Before the modifications, the LP regulator didn’t seem to make a huge difference, but I did notice that turning it up resulted in a more forceful spool valve cycle and slightly tighter groups. Since then, I’ve made several changes: I enlarged the transfer port seat on my .177, modified the needle valve inside the HP regulator body, and refined the overall airflow path. These adjustments have allowed me to run both regulators at significantly lower pressures—while actually improving results.
Performance Comparison:
- Pre-modification:
• Pellet: 13.43 grain, .177 caliber
• Velocity: ~800 fps
• HP regulator: ~2000–2200 psi
• LP regulator: ~200 psi
• Accuracy: Good, but not outstanding- Post-modification:
• Pellet: 13.43 grain, .177 caliber
• Velocity: ~820 fps
• HP regulator: ~1000 psi
• LP regulator: ~100 psi
• Accuracy: Exceptionally tight groups—often same-hole shots
Finally, on the dwell setting: I’ve kept it as low as possible while still allowing the spool valve to open. If the dwell is set too low, the valve won’t open; set it too high, and it won’t close correctly. Striking the right balance is essential.
unfortunately, the dwell setting is not exactly like increasing or decreasing a hammer spring where you’ll see a 2-3-4-5-6 ft./s increase. Maybe just an ever so slight tightening of groups.
Hope this helps more than it adds to any confusion.
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If reading above posts correctly .... both posters who modified their regulators are running LOW POWER set ups
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PS, not sure if that’s just how the EVO is set up but initial HP and LP settings seem very high to achieve 800 fps with 13.43 grain pellets. My Epoch .25 settings are HP/ 1800 and LP/ 175 for 960 fps with 33.9 grain pellets.
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I think one of us is, but I’m actually running a high power set upIf reading above posts correctly .... both posters who modified their regulators are running LOW POWER set ups
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That does seem high, but maybe because it's .177. At 1500 & 150 I'm shooting 22gr pellets at 975fps. 1900 & 180 36gr slugs @ 850fps.
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I am intrigued by the LP reg adjustment, so you have opened up the air paths in both regs now? And the final mod was to open up the spool valve poppet?Before the modifications, the LP regulator didn’t seem to make a huge difference, but I did notice that turning it up resulted in a more forceful spool valve cycle and slightly tighter groups. Since then, I’ve made several changes: I enlarged the transfer port seat on my .177, modified the needle valve inside the HP regulator body, and refined the overall airflow path. These adjustments have allowed me to run both regulators at significantly lower pressures—while actually improving results.
Hope this helps more than it adds to any confusion.
As my LP reg was not adjustable on the sub 12 version I did make an adjuster for it but found that winding it in did very little even after several turns, and it also seemed to reduce pressure rather than increase? Whether this is due to lower pressure in the HP reg making it not very responsive, I don't know?
My HP reg pressure sits around 1300psi and LP at 150psi this achieves my maximum allowed fps of 720 with a 10.34gr pellet but until I drilled out the poppet valve to 1mm the spread was always well over 10 fps now it stays around 10fps or lower.
The conclusions I draw from this is that although in theory small apertures are not a problem with HPA, but there is an application control it seems in the speed that the HPA can transfer so the aperture is a limiting factor, now I can understand this in relation to the poppet valve but not sure about the regs as the same?
Because of the speed of the air dump as the spool valve opens the poppet air feedback through the drilling is crucial to the speed of operation as the air is already leaving the gun behind the pellet and I suspect this is where calibre must come into it as this will also dictate the diameter and speed which the feedback closes the spool valve.
This is just my take on the way it works and could be completely wrong, as I am only just trying to learn the foibles of the system.
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So far, I’ve only enlarged the high-pressure regular body. I’m a little chicken now that things are working so well…. I still may.. we’ll see
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