Tuning Fx impact slug speed

[bobby]

So I bought the fix impact 30 cal about a month and a half ago and it shoots great. I then bought a slug liner to do some long range hunting on my brothers farm. It seems that I can only get the nielsen 47.2 grain slugs to fire around 930fps and when shot at 100 yards I can’t get them to group any tighter than 2 inches. I have turned the reg and hammer up and still no luck to break over 950fps. The reg is set at 150 bar and the hammer is maxed out as far a I can safely go. Ps the barrel is a 700mm. Is there something simple that I’m missing or do I have to buy something like a dual transfer port to accomplish that speed

 

[biohazardman]

Yes, a dual transfer port will usually help with the velocity. I actually shot my .25 at less than MOA at 100 yards at 740fps though it looked like the slugs tumbled at 150 yards.

Lots of power mods videos out there if you need some ideas.

https://duckduckgo.com/?t=ffab&q=fx+impact+pwer+mods&atb=v180-1&iax=videos&ia=videos

 

[JRR]

Just my experience in the need for speed and tight groups:

Ernest Rowe and Huma have the larger transfer port. I purchased the Huma and it did give give higher

FPS , but the speed is not the problem with tight groups. I started playing with the torque on the barrel

tube and found as I tighten more the group’s followed. Was very careful not to go crazy on tightening you

can flex the barrel tube if to tight. I am shooting 50.15gr at 960 FPS reg at 130 bar hammer on line 4.

you might try going back to 120 bar on reg and start over I had to do that found others here did same.

Hope this helps

 

[bobby]

Thank you very much I will start over. I will also invest in the larger huma transfer port it shot pellets absolutely amazing. I was just confused when I see all the videos of guy shooting 960 and above and I’m struggling to get 940ish. I greatly appreciate the help.

 

[JRR]

The target was with Nelson 49.5 and the crony is with the 43.8 Nelson 

 

[lancehenley1]

Ken Hicks does barrel port and probe work. Think its $45.

 

[bobby]

If I can’t seem to get the speed and accuracy I’m after I will be sending it off. Ken hicks tuned the gun back when it was a 25 cal. I just can never leave good enough alone lol.

 

[chemist63]

The Slug Power Kit and Duel Flow Transfer Port made a huge difference on my FX Impact. 25 Cal. I shot the 29.5 Grain NSA slugs in my 700mm Superior Liner at around 1000 FPS with my Regulator Pressure at around 100 Bar with hammer maxed and 4th line on the valve adjuster.

 

[bobby]

Thank you,I had ordered the huma air transfer port from Utah Airguns, unfortunately they sent me a 22 cal by mistake. I’m hopping by next weekend to get everything put back together. I am having a difficult time trying to find the slug power kit in stock anywhere I would assume that it’s a fairly hot item at the moment.

 

[bigHUN]

...I am having a difficult time trying to find the slug power kit in stock anywhere ....

With a 30 cal I assume you would need to find two springs only, one for the hammer (the older longer 57mm hammer spring C7) and one for the valve stop (C42 I picked up one close enough size in automotive supply store, btw 0.6x6.5x45), the pin probe can wait when all back in stock. The Huma dual port you would need.