I bought bulk converted 300 BLK brass from a forum private sale last year, did not know enough at the time and did not check headstamps. Now I pull the brass out and realize majority of the brass are known bad brass, CBC, PPU, RWS, PMC headstamps, for 300 BLK conversion due to thick wall. Loaded one and the neck diameter was .337, would not chamber at all. Is there any easy way to "thin" the brass neck? I know there is neck turning tool available, but they are not cheap and slow. If I put the brass back to sizing die, run a few times with the expander, would that stretch the neck thinner? I have 7.62x39 die with .311 expander, can I use the .311 expander to thin/stretch the neck?
If I end up scrap the brass, any good reliable source for 300 BLK brass? The bad part about this wall thickness thing is you won't know until loaded.
If I end up scrap the brass, any good reliable source for 300 BLK brass? The bad part about this wall thickness thing is you won't know until loaded.