View Full Version : oring on a pilot acs bolt

11-20-2006, 10:06 AM
Some of you remember when i machined 2 oring grooves in my acs bolt and i was getting alot of double feeds. Well it never crossed my mind to try only one oring. So i did this sunday ran a case a paint through the gun and no chopping no double feeds. Still had a little popcorn action goin on in my clear eggy but was noticably less than without the oring. Not that it matters much i have a new bolt but thought i would let yall know.

11-20-2006, 03:55 PM
whats the advantage to the o-ring and dont u think if you needed one spyder would have put one in?

11-20-2006, 04:08 PM
I believe he was implimenting a LP set up and trying to compensate for blow-by to achieve greater efficiency and tighter tuning.

11-20-2006, 09:16 PM
Sandman is right. I am piece by piece going lp and the acs bolt doesn't do it well. need better sealing on the chamber for lower operating pressures. I was trying to avoid a new bolt. If the orings didnt' work i hadn't lost anything because i needed a new bolt for lp anyways.

11-22-2006, 01:24 AM
i put orings on my delrin acs and it lowered the pressure by amout 15psi, and still running 280 fps +/- 1. i used a lathe and dremel w/ cutting disc, (hack saw works too) cutting through delrin is fairly hard.