Brass bulge

[Kevin Alexander]

    I just cleaned my brass and getting ready for the next loading. I noticed almost all of my brass has a very slight bulge about a 1/4” down from the base. You can’t feel it but you can see the brass is discolored at the area. I don’t think it’s even enough to measure. Any ideas what could cause it. Fired in a Browning 45-70 BPCR. Load is a 525 grain elliptical paper patched bullet, starline brass with maybe 4 firings, 76.6 grains of Swiss 1.5. CCI BR2 primers. LDPE.06 wad. Notebook paper between primer and brass. No compression. Finger seat and no neck tension.


Should I be concerned?