338 LM question

[Nefariousd]

Is it common for these to smash primers?

I ran three loads of IMR 4350 starting with 76.4, then 77.3 and finally the sierra "accuracy" load of 78.2. The only difference was I was using WLRM primers instead of 215M's (couldn't find any, locally) which is why I started at 76.4.

At 76.4 the primers looked normal with nice rounded edges
77.3 made them a little flatter but still some round edge
78.2 smashed them good but there were no other indications of pressure.

I read in one of the threads on here of someone that had a 300WM that smashed primers always and I was curious if this is normal for the 338LM cartridge?

Other Specifics 300SMK, new Lapua Brass, 1:9 Savage 110BA

 

[Nefariousd]

Re: 338 LM question

Thanks for that

 

[bodywerks]

Re: 338 LM question

Wouldn't worry too much about what the primer looks like. Just not seating them all the way in the pocket can affect how the punched primer looks.
Since I have the same rifle, I can tell you that heavy bolt lift and difficulty extracting the brass may be better indicators of pressure, although since you're running lapua brass you might not have the problem as soon as I did. My heavy bolt lift starts at only 89 grains of retumbo, and I can only get the 300 bergers to run in the high 2500/low 2600's at that charge - I was hoping for the high 2600/low 2700's...

 

[Nefariousd]

Re: 338 LM question

Thank you sir, I just sent you a PM at SS and I was gonna hit up JPeoples to see what his did.