Recent content by nervoustrig

Looks like those four found out at a level of 10.

My buddy Anton installed a big can on his gun and it also began producing 2" groups. But in fairness, his was a shotgun and distances were quite close. In all seriousness, a slight POI shift is to be expected, but if groups open up considerably, that's symptomatic of clipping the baffles...

Please pass the eye bleach.

Yes, a -006. It's prone to extrusion so use a 90 durometer if possible.

Hardening of the O-ring at the small end of the regulator’s piston is a result of thermal stress. For adjustable regulators, the same occurs with the O-ring on the adjuster screw. An elastomer with better high-temperature properties will last longer. Viton, or its generic material callout...

Agreed, there is something very enjoyable shooting an easy-to-cock rifle with a sedate shot cycle. One of my favorites is a very modest QB78 bottle conversion with a PEEK poppet and super light MDS nylon hammer. In .22 cal shooting 18.1gr at 30fpe, it’s similarly quiet and recoilless as my...

Whew, that sounds frustrating. Divide and conquer. A regulator functions by passing air until such time as the force against the piston’s large end compresses the spring sufficiently to force the small end against the seat and halt the flow of air. So start by forcing the piston to stay off...

That's a tough one to diagnose from the available information. Let's get a baseline without changing the hammer spring tension. Normally that would mean doing a full string but since... ...so instead try collecting velocities at different reservoir pressures and report back. 3 shots at...

Dressing the seat surfaces is indeed the way to improve it. It's actually not that bad, though, A decline from 124 bar down to 114 bar is a change of about 8%. Anything under 10% is usually rendered inconsequential if the gun is adjusted for the velocity knee. Has the gun been difficult to...

Either way will work in most cases. The initial goal is just to find the amount of hammer spring tension necessary to reach the velocity plateau (max velocity achievable with the current regulator setpoint). However in some cases you can get confusing behavior when starting with maximum hammer...

You are on the right track, but you can approach it as more of a cookbook recipe by lowering the regulator a bit and then dial the hammer spring tension to the velocity knee (95-97% of the maximum velocity). https://www.airgunnation.com/threads/regulator-pressure-vs-hammer-spring-tension.1133487/

It means the hammer spring tension is set a bit too light. As the pressure declines, the hammer is able to more easily knock the valve open.

Use a black Sharpie to color the contact faces of both the poppet and the valve. Apply a light abrasive* and spin them together for long enough to clear the ink from the surfaces. Wipe away the abrasive and inspect both with the aid of magnification. If there is a low spot such as a fine...

You could buy a chronograph for less than the gas plus wear & tear...but it’s a good reason to visit a friend.(y)

The general way of doing it is to adjust the hammer spring tension for somewhere in the ballpark of 97% of the maximum velocity. https://www.airgunnation.com/threads/regulator-pressure-vs-hammer-spring-tension.1133487