Tuesday I take possession of a new FX Impact MK2. Question is to tune or not?

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By “tune”, you mean modifying the gun in excess of what can be done with Hammer, reg pressure, and valve? If all you’re going to do is shoot pellets, there’s no reason to go further than stock adjustments. Anywhere in the 900 to 950 region is fine with the .25 Heavy. More velocity than that gets you nothing except excess air usage. Now if you want to shoot slugs, especially heavier slugs, then you may want to look into upgrading the power of your gun above stock. 
 
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There is an old drag racer's saying... "There's no replacement for displacement". I've been there, done that. You can soup the hell out of a 327 chevy, but don't bet the farm against a stock 454.

I've taken this to heart. If you want more, buy more. I bought my Impact X .22 with the expectations it would shoot JSB 18.13's at around 890 fps, do it very accurately, and have a good shot count. That is more or less what it was designed to do, and is exactly why I bought it.

Yup, you can max out the hammer spring, add some weight to the hammer, crank that reg to 160, 170, 180 (if you feel lucky), hog out the probe transfer port, add some plenum space, but why??? If you want 60 fpe (33.9 gr ammo at 900 fps) out of a .25 get a RAW. It's made at those specs. Or some other PCP that does what you want. If max power is what you want.

I applaud those folks who know the Impact inside and out, and can mod the heck out of them. It seems if they get a leak, which is a concern of mine, and has happened, no big problem, rip 'er down add a an o ring here or there and it's business as usual. 

As a side note. Many years ago in a land far, far away ( actually it was in the 1960's) I had a Smith and Wesson model 29, it was a 44 magnum. It was made by S&W with help from one Elmer Keith. His favorite load was 22 grains of 2400 behind a 250 grain lead bullet, which has now been determined to be over the working pressure of this gun. I naturally decided the big load was just what I wanted. Needless to say that gun was trashed in just over 500 rounds. And I mean trashed. 
 
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There is an old drag racer's saying... "There's no replacement for displacement". I've been there, done that. You can soup the hell out of a 327 chevy, but don't bet the farm against a stock 454.

I've taken this to heart. If you want more, buy more. I bought my Impact X .22 with the expectations it would shoot JSB 18.13's at around 890 fps, do it very accurately, and have a good shot count. That is more or less what it was designed to do, and is exactly why I bought it.

Yup, you can max out the hammer spring, add some weight to the hammer, crank that reg to 160, 170, 180 (if you feel lucky), hog out the probe transfer port, add some plenum space, but why??? If you want 60 fpe (33.9 gr ammo at 900 fps) out of a .25 get a RAW. It's made at those specs. Or some other PCP that does what you want. If max power is what you want.

I applaud those folks who know the Impact inside and out, and can mod the heck out of them. It seems if they get a leak, which is a concern of mine, and has happened, no big problem, rip 'er down add a an o ring here or there and it's business as usual. 

As a side note. Many years ago in a land far, far away ( actually it was in the 1960's) I had a Smith and Wesson model 29, it was a 44 magnum. It was made by S&W with help from one Elmer Keith. His favorite load was 22 grains of 2400 behind a 250 grain lead bullet, which has now been determined to be over the working pressure of this gun. I naturally decided the big load was just what I wanted. Needless to say that gun was trashed in just over 500 rounds. And I mean trashed.
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Love that Elmer Keith story, your answer was thoughtful and insightful and one I will take and follow.

Ron
 
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By tuning I mean making adjustments and not modifying any hardware.

It have the 600mm barrel .

My Warcat in .25 reg set at 145 shoots jsb heavies at 905 in a stock gun 

I was hoping the Impact could get up to mid nines.

Thanks guys
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There's nothing wrong with making the adjustments, especially if your gun is not properly set up as delivered (mine wasn't). I would first see how it's shooting out of the box and just follow the normal tuning as outlined here and in the owners manual.

My 30 Cal Mark II came with the reg pressure set very low (120 bar) and the hammer spring adjuster backed way off. Why, I have no idea-- but it was fresh from FXusa via Airgun Depot and the rifle was shooting less than 700 fps. Within a few minutes I had the 30 Cal shooting 870 fps and amazing groups at 50 yards and beyond. Been tweaking it a bit higher, but really it is the accuracy and repeatability that makes me grin the most, every time. 
 
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Centercut, I have tuned several .25 Wildcat Compact's to shoot the JSB 34 grain MKII's at 61 fpe...but that required a Huma reg set at 170 Bar. a softer valve pin spring, a heavier hammer weight, and enlarging the transfer port to 6mm. Shot count from 230 Bar fill was 16 full power shots before falling off reg.
 
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By tuning I mean making adjustments and not modifying any hardware.

It have the 600mm barrel .

My Warcat in .25 reg set at 145 shoots jsb heavies at 905 in a stock gun 

I was hoping the Impact could get up to mid nines.

Thanks guys
Click to expand...

There's nothing wrong with making the adjustments, especially if your gun is not properly set up as delivered (mine wasn't). I would first see how it's shooting out of the box and just follow the normal tuning as outlined here and in the owners manual.

My 30 Cal Mark II came with the reg pressure set very low (120 bar) and the hammer spring adjuster backed way off. Why, I have no idea-- but it was fresh from FXusa via Airgun Depot and the rifle was shooting less than 700 fps. Within a few minutes I had the 30 Cal shooting 870 fps and amazing groups at 50 yards and beyond. Been tweaking it a bit higher, but really it is the accuracy and repeatability that makes me grin the most, every time.
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Yes Hyperdave those are the adjustments I was asking about, I didn't totally clarify my question correctly.

RonT
 
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First of all, get the gun in your hand and after feeling happy and the initial feeling of bliss wears away... Then you'll want to shoot it, of course with your scope mounted etc. Once zeroed to your distance and so forth, shoot it like it came and get accustomed to it. Check with a chronograph and a caliper, now record all the settings that the gun came with. Look at Ernest "Tuning Video" for this. Now, you are on your way to deciding what you want to accomplish with your Impact and if you need to fine tune it. Most of them will need some type of adjustment to get it to your liking. That is, to bring that SMILE on your face. Good Luck and have lots of fun with it.
 
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Ron T-

Congratulations! I hope to be in the same situation within the next 2 or 3 weeks myself. If you don't mind me asking, how long ago did you place the order? I am currently on a waiting list…

After some extensive reading and video watching, I think I have come up with a plan with my incoming Impact MkII. Mine will be a 700 mm, .25, and hopefully will have both a pellet and slug liner appear with it. Can you hear my foot tapping in the background… :)

My plan of attack is:

1. Disassemble and clean barrel. This should be no big deal and I need to know how the barrel is changed out. Everyone, including the factory, states this is badly needed.

2. Once it is cleaned and reassembled I will install the separate moderator on to the barrel and eyeball all appears clear through the bore/moderator.

3. Install my scope. I will also check the trigger and adjust if necessary using factory guidelines. At this point I just need to be close, I expect I will revisit this as things settle in.

4. (Charge the cylinder to full charge) I will start my shooting routine by 1st noting the settings as they come set from the factory. My personality requires me to write most things down. Who the H knows when I will get back to the same availability of time, and I want to be able to continue and not have 2 start over… 

5. I will start with JSB 25.4 pellets and shoot several groups, once the rifle is zeroed. After speaking to a factory technician I understand that the 1st 3 to 5 tins of pellets are a reasonable amount to put through it before expecting it to shoot the groups it is usually known for. Somewhere in here I will also try the JSB heavies.

6. If I am satisfied the groups at this point, I will work on chewing up some paper, chronograph things, and start developing some consistent ballistics data to use in the field. My scope should reasonably accommodate 150 yards shots using internal hashmarks. By this time I would hope to be approaching 1000 rounds downrange.

7. If the groups are not acceptable then I will move towards a change in the factory settings. Several people here have given you good information on what you can expect, and what their experience in the range of adjustment settings is.

While I normally have had to wait for a call back, the factory technicians have been straightforward in answering my questions and I expect this will continue if I have any issues with the new firearm. I doubt if there are too many problems that they have not seen before – one of the benefits of seeing hundreds if not thousands of these guns go through. If you have too many issues I am confident they will probably have you send it in. I have no experience in their turnaround time.

If you have not reviewed the videos that are posted here, airgun 101, and on YouTube concerning the tuning of the rifle, I would sincerely recommend them. There are at least 3 or 4 that are somewhat technical, but understandable to people with a reasonable mechanical inclination.

Again, welcome to the adventure, I will look forward to hearing how it goes for you. Hopefully everything will be positive, you'll have great groups, and use very little air… :)

Please let us know how it turns out. A lot of good shooters and tinkerers/mechanics are here to help you be successful. Good luck, good shooting. Hi-vel



PS- On Airgun 101, Air Hunters posted a recent video (Shooting Pigeons from Benchrest I think) and Roelf shows his settings that he is using on his FX. Nice!
 
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Orderd from Pyramyd Air 7/20 

I have a FX Warcat .25 thats a great gun I came close to selling and if it don't sell this time?

I will keep it. The Impact looks like an awesome gun also, so I had give one a try, airgun shooters

seems to like to buy and sell or trade a lot, but I have a feeling the Impact is a long term keeper.

You sound very excited waiting for your Impact seems this is one of those guns that have that

effect on owners.

RonT 
 
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Centercut, I have tuned several .25 Wildcat Compact's to shoot the JSB 34 grain MKII's at 61 fpe...but that required a Huma reg set at 170 Bar. a softer valve pin spring, a heavier hammer weight, and enlarging the transfer port to 6mm. Shot count from 230 Bar fill was 16 full power shots before falling off reg.
Click to expand...

Exactly my point. Without extensive mods it doesn't shoot 61 FPE. I agree of course that it CAN be done. Hey, since when did you only fill to 230 bar? And 16 shots? If I wanted only 16 shots I'd buy a Marauder. LOL. ;)
 
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