Gas shotty help needed.

[Caveira]

I've got an ACM M500 5 shot gas shotty that's leaking.

It had a slight leak when I got it second hand, but lived with it. Having to re-gas before getting into a firefight got on my nerves, so I decided to strip it and see if I could find the problem.

Bottom line, it now vents all the gas straight away, but I can't find any o-rings that I've caused damage to. Also, I've ptfe taped any screw fitting, so I can't work out why the gas is unable to be retained.

Anyone got any ideas before I have to send it away? I really want to get this back up and running for the weekender.

[heroshark]

Re: Gas shotty help needed.

soak all the seals in automatic transmission fluid for a couple of days get rid of the ptfe you shouldnt need it .And buy a box full of assorted orings off the bay as back up. If you do swap them out soak the new ones too before you use them. Store the gun gassed, and cocked. Keep it well siliconed. I made an addaptor like a gass filler nozzel so I can put it streight into the gas chamber. As much as I love mine these guns are truly a pita ,hope this helps

[Caveira]

Re: Gas shotty help needed.

I've swapped some of the o-rings and soaked the ones that I'd left, but I hadn't thought to soak the new ones going in.

I always leave gas guns and mags with gas in them, as well as putting a few shots through every few weeks using ultra to keep the lubed.

Surely, keeping it cocked will unnecessarily weaken the hammer spring?

I'll try pulling the o-rings and re-soaking unless anyone else has an idea.

[Caveira]

Re: Gas shotty help needed.

Done some more research and it looks like over-tightening some of the parts forces other parts not to fully close.

So, waiting for a new selection box of o-rings (400+ 3-50mm for £6.70 from the bay) then I'll pull it apart again, soak the new rings, put it back together and try again.

[weekenny]

Re: Gas shotty help needed.

I'd not store it cocked like you say it'll weaken the hammer spring.

The trick is tightening the brass part of the valve enough without going too far. Start with it nipped up then back off at a fraction a time while trying to gas between adjustments. Once it's gas tight refit and fill then use all the gas in it to see how it suits. Then remove and adjust again if it's showing problems.

Takes some fiddling but I've done two now that have been gas right for a couple of weeks now and they are stored not cocked. If your having trouble storing it cocked I'd suggest tightening the brass bit just a little.

[Caveira]

Re: Gas shotty help needed.

Sorted.

A good soak, some new o-rings and loosening the valve a touch and it holds gas for days.

Thanks for all the help guys.