Hammerli Master Issue

[steve medlock]

The most likely issue is that the seal in your auto-release cap is failing - recently I replaced the crumbly seal with an O-ring and it works. It's also possible that yours is set to release far too 'early' (meaning at too high a residual pressure), leading it to release at full CO2 pressure. The VintageAirgunsGallery instructions for the auto-release cap (page 9 of link below) and its diagram (page 22) apply. Though the Master triggers and firing valves changed through the years, I've only seen one version of the auto-release cap. Note the instructions tell us to deactivate the release feature when piercing a cartridge (rotate the rear portion until it pops backward). After the gun is charged, push and turn to activate the release feature.
https://forum.vintageairgunsgallery....ual/#post-3763

Don R.

Hi Don,

Yes, I did try adjusting the screw but that didn't help. It would appear that there are two or three variants of the auto release device. This one looks externally similar to the diagram but the internals are different based around a ball valve. It doesn't turn or spring back as the instructions suggest.

[steve medlock]

I might just have sorted this......It suddenly dawned upon me that the auto release had been re-assembled incorrectly - the circlip had been put back on the wrong side of the screw housing. With this bit in the right place, the rear part then turned/locked as per the instructions. I also added a weak spring to hold the ball in place against the inner seal. It still leaked however until I put a stiffer spring in next to the ball and now it seems to be gas tight, fingers crossed. If it hasn't lost the gas over night, that may be job done.

[draitzer]

There's something to learn every day! They couldn't resist using a ball in the cap as well as the firing valve. Thanks for the photo - glad you've been able to resolve it.

Don R.