I'm looking into getting another Air rifle and have a few on deck. But I would like to know if anyone has tuned a FX impact in .25 to shoot the jsb 33.95 at 60fpe or 890fps. I've heard different stories about it being able to that so I thought I would ask and see if there is any real world stories. Thanks
FX impact .25 question.
- Thread starter YamahaR1
- Start date
Yes not to difficult to do. Ernest is the man to talk to. You need one of his larger and stronger valve seats. He is currently getting some made of titanium.
If you mill the valve housing to get a slight increase in plenum size and a slight increase in hammer weight you’ll get there. .
I’m shooting the King Heavies at 890 and haven’t got the vs yet. Just milled the valve housing and 2gram hammer weight.
Also need to increase the size of the transfer port in the barrel.
If you mill the valve housing to get a slight increase in plenum size and a slight increase in hammer weight you’ll get there. .
I’m shooting the King Heavies at 890 and haven’t got the vs yet. Just milled the valve housing and 2gram hammer weight.
Also need to increase the size of the transfer port in the barrel.
Upvote 0
It isn’t worth it for the smooth twist barrel as accuracy will go at those speeds. I have a Lothar Walther poly barrel.
It will be nice to have the power when the smooth-x is available.
Shot count is still respectable I haven’t ever worked it out exactly.
It will be nice to have the power when the smooth-x is available.
Shot count is still respectable I haven’t ever worked it out exactly.
Upvote 0
86 shots at 52 ft/lbs 830FPS
Reg set between 120-125 bar
bored out valve housing
bored out transfer port hole
no accuray once you get above 860 I can take mine to 920 fps but accuracy sucks. 830 is perfect!!!
Reg set between 120-125 bar
bored out valve housing
bored out transfer port hole
no accuray once you get above 860 I can take mine to 920 fps but accuracy sucks. 830 is perfect!!!
Upvote 0
I have been testing my .25 impact with different regulator pressures for the last days and I find the same results you did. Reg pressure set at 120-125 yields to 830fps.
Reg is max out on pw 5 VS set by the 4th line.
The accuracy at 50 yards is really good. Haven't try it at 90 or 100.
Upvote 0
Sounds like the sweet spot for that round in the impact is 830fps. Sounds like shot count is real high too at that velocity. Just can't find any dealer that has them in stock. Seems like they would have gotten ahead of that by now considering they are a couple years old.
Upvote 0
I have actually done quite a bit of testing on all calibers and just to confirm like everyone has said, it wont shoot well at those higher speeds. Although I do know a guy in the UK who shoots his at 880fps and he said it is his best shooter. I however have not been able to duplicate those results. He has 33.95gr MKII, Reg 145-150, valve showing 3 lines, power wheel maxed out and 880fps.
I can also confirm that to get some higher speeds, you will need ER's bigger valve seat. I have gotten my .30 up to 920fps.
I can also confirm that to get some higher speeds, you will need ER's bigger valve seat. I have gotten my .30 up to 920fps.
Upvote 0