Since I have an endless supply of empty beer cans in my workshop I wanted to try and use them for my 300 Blackout loads, a Lee 155gn PCed bullet for plinkling up to 200meters.
I made myself a gas check punch tool for the single stage press which works just fine, but since the beer cans are quite thin walled the checks wont stick to the bullet base even after passing through the sizing die. Despite that I milled the gas check groove in the mold so that it matches the thickness of the GC.
Anyways, with a small bellmouth on the case made by modifying the powder drop die I can just put the GC on the bullet when placing it on the case mouth and seat the bullet so far that the case neck tension holds the GC in place.
So far it seems to work just fine, I havent pushed the velocities beyond 1700fps yet but they group just fine and no signs of leading.
Is there a downside to these thin walled gas checks? I assume they drop off as soon as the bullet leaves the barrel but why would that affect accuracy in any way?
A single copper gas check bought through Brownells in Sweden cost almost as much as the powder and primer together in the loaded round, so I am really saving money here.