No. 4 Mark I splits cases

[Joe Boleo]

I picked up a mint No. 4 Mark I .303 Enfield from WWII at a gun shop and took it to the range. The first reloads were S&B cases with 150 grain .311 bullets and moderate charge of IMR 4895. Accuracy was great and two of the S&B cases had complete head separations. I am sure glad the Enfield is gas proof. I had no idea of the case separation until I worked the bolt. The rim came out and the case body was still in the chamber. I used a loaded round to go inside the case and extract the case from the chamber. Eight more S&B cases worked fine. The tenth S&B case separated and I removed it. The reloads were loaded once or twice and were neck sized only.

I ran some reloads with Federal cases and everything was fine. I intend to replace the number 1 bolt head with a number 2 and see what happens. At this point I do not know whether it is a gun problem or an ammo problem. That was my experience at the last range session. Take care...
Joe