Low velocity on first shot

[rawbutter]

I'm getting some first shot drop off on one of my pneumags. It has an RT valve with Level 10 and an RT on/off. I seem to remember that first shot drop off is usually caused by a leak with that little o-ring that goes inside the on/off assembly, but I wanted to check before I start fiddling with it.

Usually whenever I get any problems with my mags, I start by changing all the o-rings, but I just did that over the summer. Don't want to do it again. I'd much rather just change one.

Pics probably won't help, but I'll add one anyway to show off. 😅

[superman]

correct, I would check the small one inside the on/off. It will cause the dump chamber to leak through the bottom of the on/off.

[Spider!]

I always considered fsdo on a mag as two things at once. A leak from the power tube or on/off, plus a sticky reg piston that isn't making up the pressure very well.

[Alexndl]

I was here for the picture, thanks for adding one!