Black cases from burnt powder

stovepipe · Posted: Fri Sep 30, 2011 1:19 pm Post subject: Re: Black cases from burnt powder

More pressure = better seal.

Those are BIG jumps going up a full grain atta time! Yikes! Try .5 or .25gr jumps instead.

Size the neck, trim and burr anyways, even if ya cant cram a bullet back in. Neck may work harden and stop springing back as much- but I could be wrong about the metalurgy, just ask Chambered!

PaulS · Posted: Fri Sep 30, 2011 3:29 pm Post subject: Re: Black cases from burnt powder

How tight is the chamber in the neck area?
I had a gun that I had to polish the neck area to get the needed clearance. I didn't want to trim all my cases so I polished the neck of the chamber.
The way I found the problem was I was getting the first signs of too much pressure and yet the neck was not expanded enough to let a bullet slip in after it was fired.
Paul

clembob · Member Joined: Jul 10, 2011 Posts: 28 Location: UK

The big 1gr jump is to first get the best group over the complete range for thae powder being tested and then to see if the group tightens up by going .5 either side of the group in .1 jumps ie if 41 was the best group then load 39.5.6.7.8.9 41.0 41.1 41.2 41.3 41.4 finally 41.5.
I will have to measure the chamber not thought of that being thight.
Ta Mark