FX Impact barrel thumb screw quick mod.

[Jack.K]

Here is a quick tip for Impact owners with barrel locking screw issues. My impact shoots great after the initial leak problem. I have put over 2000 JSBs through its barrels. I love the gun but the thumb screw backs out after shooting a few magazines. Since the gun has lots or o-rings why not add another one. LOL
I installed an o-ring over the barrel locking screw. It gave just enough rubber berween knob and the block I didn’t wanted to use thread lock since I have multiple caliber barrels. The o-ring I used were 10mm x 5mm x 2.5mm. This worked very well for me. Quick and cheap fix.

 

[Paio]

Does it keep the screw pressure all the way to the barrel avoiding the thumb screw to unscrew? That little amount of rubber (2mm flat, after pressure perhaps) does not interfere between the thumb screw and block avoiding full contact of the screw into the barrel indicator hole? How many shots have you try so far? I am not doubting... Just going a little deeper. Nice mod for sure. 

 

[Jack.K]

"Paio"Does it keep the screw pressure all the way to the barrel avoiding the thumb screw to unscrew? That little amount of rubber (2mm flat, after pressure perhaps) does not interfere between the thumb screw and block avoiding full contact of the screw into the barrel indicator hole? How many shots have you try so far? I am not doubting... Just going a little deeper. Nice mod for sure.

The o-ring got compressed to about 1.75mm from 2.5mm when it's pressed against the receiver block. On my Impact this simple mod is keeping the screw from unscrewing out even after about 100 shoots. I placed a blue tape arrow pointing to my barrel as my reference to before the o-ring and after the o-ring. This also lets me know if the screw has moved or not. I think the that o-ring pressure is helping to keep the screw from "vibrating" out. 

 

[fe7565]

Some drop a ball bearing in there and tighten the screw on top of it. I think there was a post here on AGN.

 

[Jack.K]

"fe7565"Some drop a ball bearing in there and tighten the screw on top of it. I think there was a post here on AGN.

I didn't want to put more pressure against the barrel with the thumb screw which might change the POI. 

 

[Verve]

Going to give this a try as its probably the simplest solution to the problem.

POI, on my Impact changes, the moment this screw comes loose and when retightened. Middle target is last 6 shots from the mag with this screw loose. 18 shots with fps range of 895-905.

 

[Jack.K]

"Verve"Going to give this a try as its probably the simplest solution to the problem.

@Verve
How did it work for you?

its been a month since I did this mod on my Impact and the barrel thumb screw is still locked in after another tin of JSB. 

 

[Verve]

Jack.K

"Verve"Going to give this a try as its probably the simplest solution to the problem.

@Verve
How did it work for you?

its been a month since I did this mod on my Impact and the barrel thumb screw is still locked in after another tin of JSB. 

Hi Jack
Thanks for the reminder. O-rings is on order now, when delivered will try it. Been busy with custom shroud so not really paid attention to this.

 

[GQ]

Mine have not move at all after 900 shots with the o ring.

 

[Drumsnguns]

Man, I love the "simple fix"...well done! I'll be trying this!

 

[Jack.K]

The blue tape that I have on the thumb screw also helps me identify how far to tighten the screw (or not over tighten) and if it backs out over time since it's pointing at the front of the gun.

 

[Pestassassn]

Will be trying this very soon, as I've been having the same problem with the Impact I recently received. Thanks!