I have a fx impact mk2 sniper 30cal looking for specs for a hunting setup for med size game. Turkey, coyotes ect just shot a short thread but the fpe seems extremely low at 17.8 down to 17.6 in this short string with fx hybrid slugs 44.5 gr. Any advice would be greatly appreciated. Thanks 
Hybrid slugs 44.5 gr
- Thread starter Dustin
- Start date
You need to tune it a bit more to get rid of that low first shot. That first shot was 79fpe vs your last shot being 85fpe
Upvote 0
Your FPE is 83.47 at an ave speed of 919FPS. I think you are confusing your velocity spread with energy numbers. These are good numbers to knock things down with, have at it.
Upvote 0
Not sure the Chronograph needs to be recalibrated. Did you shoot indoors or outdoors? And is there a big difference between the inside of your home and outside if you did shoot outside?
Upvote 0
No - he is referring to tuning the airgun to remove the first low shot. You may not need to do that though as shots 2-4 are pretty good. IIRC the Impact Mk2 was known to suffer from reg creep. This leads to a slow first shot after sitting for a bit. Next string you take just fire off a blank shot before you start to chrono.
In terms of the fpe reading. Be sure you are not confusing fpS with fpE as noted above. I do not see fpE in any of the screenshots you posted. Also - for the profile you are using in the FX app, check that you have the right projectile weight entered.
Upvote 0
A lot of us seemed to have that first shot low problem with the first and second gen Impact's. It is from a couple of minor issues, including reg creep and stiction of the o-rings from sitting. Aside from cleaning, polishing, and lubing the reg components, I found that polishing the valve pins and bores, and the applying ptfe lube instead of clear silicone helped tremendously.
Upvote 0