Tuning Impact C1

[caesar]

When I tighten my C1 (it came loose) it sticks out less than 6mm. 5.7mm to be exact. Is there a better way than just using permanent loctite to “set” the C1 where I want it? Gun came with the C1 loose and I’ve been fighting with it since.


It’s a .25 Impact MK-II setup to shoot heavy slugs. Lots of modifications to improve power and efficiency. More than 6-6.5mm and there’s power loss, same goes for less than 6mm too I’m finding out. Especially with the slug power kit installed.

 

[biohazardman]

I just used the blue locktight on my .25, modified like yours, and have never had a problem in 6K+ rounds since. I think there are threads in the hole in the C1 on mine though so I could use a tiny set screw if I needed to.



EDIT; I almost fergot.

Ernest has a neat little trick that I have used in the past also. Put a small piece of an o-ring into the threaded hole of the C1 before you screw it onto the rod. Use the locktight as well. The o-ring will werq like a lock washer to hold the c1 on the valve rod when it is tightened up.

 

[dannya1a]

yes it will. I used Ernest trick as well. held pretty well. had issues before in this area also. kept going loose on my shooting heavy self-cast slugs.

 

[Glem.Chally]

Loctite has worked fine for me.

 

[Vetmx]

Just put a dab of blue loc-tite on it and snug it to 5.7. You’ll be fine because now you have 2 things holding it in place. What that -.3mm does to the gun is way better than what happens when it starts working it’s way out and you waste a bunch of lead before you figure it out. I just put my gun back together and snugged it instead of having it float on threads relying on loc-tite. Gun tuned fine.

 

[bigHUN]

Yesterday at range I started loosing speed, slowly from 900 to 840 ish maybe after some hundred shots, the C1 came to my mind first. When I got home I check it and it within 6.5-7 mm tolerance I can live with. Next I will have to check the Reg, I never toke it out yet and assume it got clogged from my last SCBA refill I knew it was sucking up some moisture.

To add a story to C1, I would really not worry about the exact dimension, I have custom springs specs both on hammer (this one is stronger) and valve (this one is softer) and I know where is a set point...my valve knob is way out at the oring that means the C1 travels longer, but I put a rubber ball there just to make sure not to overtravel.

Don`t worry the valve oring will not overtravel 1mm