I have had to throw out a bunch of shell casings in .270 Win. for my Mossberg 4 X 4 rifle. Some of these loads are averaging at 4-6 loadings only and then splitting, the brands are Sellier and Bellot, and Serbian PPY. The splits are near the neck only.

I used to shoot old military surplus ammo and this was real common with them. Have been hand loading Norma, Remington, and Winchester brass in the past in different calibers and other rifles, and have never seen commercial brass do this.

I use PPY (Serb.) ammo exclusively in the Mossberg with a box of S/B to date. Wondering if it is the brass quality, have
read alot of complaints on the S/B being thin and splitting. Tried PPY in my Remington 700 in .308 and found it bad brass, but was good stuff in my AR-15 in .223.

Wondering if there is an error in my re-sizing of the brass during reloading or the brass, rifle chamber, being the issue?

Thanks.

A good read! Slide on down to the part about Fred Barker and annealing cases with a candle.
Link here.