338 Lapua Hornady Case Binds Chamber After Firing

[Double Naught Spy]

I had the opportunity to help break in a buddy's new McMillan G30 chambered in .338 Lapua. It was my first experience with the caliber and with a brand new McMillan. The gun was terrific. The really expensive Lapua ammo shot great. The Hornady 285 gr BTHP match ammo shot okay. Where the Lapua had a standard deviation in velocity of a few feet per second, the Hornady was over 100. The group sizes for the Hornady were + MOA and the Lapua was sub MOA. The Hornady ammo was about 60% of the cost, however.

The only real problem was with the Hornady ammo and only after firing. The bolt on the G30 required a good amount of force to open (raising the bolt handle) and then the shell would extract just fine once the bolt was pulled back. With the Lapua, the bolt opened smoothly and the shell extracted just as smoothly.

Neither of us knew why there was a problem with the Hornady ammo. Anyone have a clue as to why the bolt would not readily open after firing?

 

[bullspotter]

sticky bolt could be from an over pressure round.

 

[Double Naught Spy]

Thanks for the response. We did look for that. There were no obvious signs on the brass or primers. Is there something else we should have looked for that would indicated an over pressure condition?