Excessively hard trigger pull + hot shots

[ljpiller]

I have been restoring a very old Level 7 Automag and I've noticed that on CO2 (I haven't tried it on HPA) I will occasionally get some very hot shots (around 350-400 fps) accompanied by a really heavy trigger pull on those shots. I have never seen my marker leak out the back - isn't it supposed to do that in order to prevent such hot shots? My velocity has also been rather inconsistent +/- 25 fps.

Is there some part not functioning correctly?

[Coralis]

sounds like you are getting liquid CO2 into the valve ... does it have any of the following: expansion chamber , anti siphon tube, palmer stabilizer etc ?

[ljpiller]

Its just a normal tank coming out of the old back bottle setup. Liquid is probably the case.

Hopefully that can account for the inconsistency also. It is only 50 degrees outside when I'm testing it so that doesn't help. Thanks

[Bagheera]

The old school 'fix' was to get an extra long braided hose and loop it a bit before it gets to the valve. An expansion chamber is a much better idea though.

[ThePixelGuru]

My guess is regulator creep, which is when your regulator seat goes bad and lets a slow leak of air into the chamber. The way to tell if this is happening is to chrono a few shots, then let it sit for a minute and chrono again. If that last shot is hot, that's because while it was sitting the reg seat let more air in than it should have and raised the pressure in the chamber, causing that hot shot. If that's the case, replace your reg seat and all should be fine.

[Lomarandil]

I'm also going to say Regulator seat, although I'm sure liquid CO2 wouldn't help

Lo

[athomas]

I second the regulator seat oring being bad. Replace this and it should be fine.