S&W M&P 40 Mod 2.0

[bdb242]

I haven't read all the posts, but those primers are not flat, and show low pressure.

The issue was the firing pin indentation is missing on the primers! All you can see is a scuff mark from the bolt face where the firing pin hole is. That is what I meant by flat primers. You need to read all the discussion concerning this post. The loading data post shows low pressure but also included a warning about high average pressure starting at 9.9 grains of Longshot with this bullet. I have loaded since the 60's, blown up a pistol @ -5* when a particular powder detonated instead of burning as smokeless powder should.

 

[Walkalong]

The issue was the firing pin indentation is missing on the primers! All you can see is a scuff mark from the bolt face where the firing pin hole is.

Ah, I see now, pic is blurry. Still looks like low pressure though