FX Impact tuning

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dc8cappie

dc8cappie

Member
Aug 27, 2019
363
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Palm Harbor, Florida, United States
I’m a little bit irritated at myself. I’m doing a retune of my Impact .22. At this point settings are, 83bar, hammer spring 18.76mm@max,power tuning adjuster 8.35mm. Speeds after the adjustments on Max is 875fps and I’m shooting at power wheel #5 and 860fps. The numbers after the work are 875fps with a max spread of 8 and SD 1.9. I still haven’t been able to get hole in hole at 50 yards. Shooting on PW #5 and 860fps 50 yards this is what I get. 
Any help will be appreciated.

1593956899_15364106175f01da2327f6b1.67998994.jpeg

Please note the third shot of 5 on the left was due to wind lull, wind was left to right quartile from slightly form the rear at 15-18 mph.



Moderator, feel free to move if in the wrong category.
 
JSB 18.13, hammer spring tension has always been a question. I don’t have a good understanding of which is the proper tension direction for more consistent releases of energy. When I received the gun the regulator was 90 bar and the gun shot the 18gr at 905 on PW#2. The gun had a definite jar when fired, hence my retuning. 


These shots are made bench, bipod and sand bag. I started the tune with a FPS of about 935, then used the PS tuner to get the 875fps. Did I do it incorrectly?
 
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Check out Ernest row’s tuning video and the approach.



Also please provide as much details on your impact as possible. 83 bars for non power plenum impact is about right but with power plenum is a bit overkill.



example: my impact has power plenum and I drop regulator down to 50 bars and hammer spring to 24 or as Low as it can go before it doesn’t engage the power wheel anymore. Even with that I still have to limit my speed with valve down to one line with 16 grain JSB. 
 
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I should have had the following in the original post. FX Impact MK 2 with power plenum and 700mm barrel.


One tine I tried was: 82 bar, power wheel 4, tuner adjuster 8.88mm, hammer spring 17.49mm @max shooting at 927fps. It seemed to throw an occasional flyer.

Ihave one now looking pretty good. Get out tomorrow and see if it repeaters yesterday’s.



Emailed FX main asking what the allowable pressure range is on the new model regulator. If they answer I’ll post it here.
 
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Question, FX USA says, under 100bar voids the warranty. So, what really is the allowable bar Range on the new regulator. Oh, I have the new Impact with PP.
Click to expand...

FWIW, my .22/700mm wpp Impact came factory tuned to shoot 15.89 JSBS at 915 fps with a 70 bar setpoint.
Click to expand...

Thanks, I thought I’d seen a post that someone else said the same. Also Tor47, I’m trying to fine tune the trimmer at 845fps now. Looks promising at 50 yds. I made a small trimmer adjustment after I got home like a dummy. When I get back out I’ll check it again and if the wind stays down, I’ll try it at 100 yards. Oh ya, I’ll keep my fingers off the adjusters!



PS, thanks all! 😃
 
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Its much better to hit the skirt/rear of the pellet with a large blast of air, close the valve early, and let the projectile coast on the remaining air, so as the pellet nears its exit, pressure is minimized to reduce turbulence upon said exit.



This effect also helps correct imperfections in the skirt by blowing them out uniformly into your groves and lands of the bore...



This effect is also far more efficient, generally providing larger shot counts (ideally achieving between 1.3-1.4 fpe/ci...with a .22 cal and 700mm barrel maybe push that to 1.5 fpe/ci..)



This effect also causes slight reduction in the jet effect / recoil



You will want to use the valve limiter to bring fps down by 20-30 once you set things all up, so if you're goal is 880 for example, you tune for 900 with valve adjuster all the way out, and once achieved you bring fps back down with said adjuster to 880...HTH
 
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Question, FX USA says, under 100bar voids the warranty. So, what really is the allowable bar Range on the new regulator. Oh, I have the new Impact with PP.
Click to expand...

Yeah.. 
I've known about that 'warning' forever too.. 
Then FX switched over to the new version / A.M.P. regulator, so who knows what the deal is now..
My Impact MK-22 w/ PP shipped to me pre-set at 85 bar. That made me paranoid right from the start.. 
[Especially since I've continuously had issues trying to dial the reg pressure up-or-down for fine tuning]

Since there's no concrete info on the AMP regs [no info in the owner manual, pdf online, etc]
I set mine to the 'min' 100bar - just to be safe.

But back to reg-pressure and accuracy/consistency..
When the reg was initially set to 85, I did some out of the box testing, 
at Indoors / at 10m, I was getting pellet on pellet on pellet placement.

So just a heads up - Under 100 bar of reg pressure should still be Very accurate/consistent. 

Sam -

PS: Pellets used: .22 cal JSB Hades, and Crosman Premier Hallow Points
 
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I was shooting today again. Gun is shooting at 848 FPS, chronograph says SD 2.0 max spread of 7 with 10 shots. I watch many pellets in flight and of the ones I watched, I never saw a spiral. Saw some hole in hole with groups under a inch at 50 yards. Again I’m outdoors, started with null to 2-3 mph winds. Shot at 100 yds but it was down wind with 8 to 15 mph with variations to the right pushing the pellet 4.5” right level with point of aim.



There are two ranges near me. One is outdoor with firms all around for $20 all day. The other an indoor range at $27 per hour. Thing is, the indoor seams anti anything air powered. The attitude I got looking for dovetail to Picatinny adaptor for my gauntlet was unfriendly. I’ll try the outdoor range hopefully I’ll get some calm winds and see exactly what gun shoots at 100 yards. If the results still look good, I guess I’ll go to 100 bar start at 880 ft./s and put it down To 850 with the tuner. Of course this means I’m starting all over again from scratch.
 
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