Over pressure signs?

[McHoss]

Today I fired some test loads of 9mm. They were loaded with 4.6gr of Bullseye under 115gr Berry’s plated RN bulletes and seated to 1.125 with CCI 500 small primers. Shot through M&P9.
There is a “tear drop” pattern that matches the firing pin and breech face left on some of the rounds. They fired perfectly with zero FTF or FTE and were very very accurate.
The picture are of the worst of the batch of 50 and the camera seeems to have enhanced the detail. It seems less apparent to the naked eye.
Any thoughts?

View attachment 177354

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[Alpheus]

My M&P9 does the same thing with factory ammo.

 

[Ganderite]

Your load sounds reasonable. About 90% power.

 

[Snider shooter]

Looks normal to me. Some guns leave unique markings on primers. Primer edges rounded,normal.

 

[4n2t0]

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[Sqr]

Your load sounds reasonable. About 90% power.

but bullet seating depth and crimp can result in overpressure signs even with the correct powder charge.

 

[McHoss]

but bullet seating depth and crimp can result in overpressure signs even with the correct powder charge.

The seating depth I’m using (1.125) is well above the min for 9mm and any load data I’ve seen. So I doubt that would have much impact. The Bullseye doesn’t come close to filling the case so compressed loads aren’t a concern. I use a Lee FCD and only turned it about 1/4 turn after it touched the case neck. So a very light crimp in my opinion. Maybe I will lighten the crimp slightly and see if that changes things.

 

[McHoss]

Question.....are CCI primers known to be softer than others?
I looked at some factory brass fired from the same pistol and it shows the same markings but maybe slightly less pronounced. Or maybe that’s just in my mind. Lol.

 

[4n2t0]

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[4n2t0]

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[4n2t0]

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[Icefire]

Primer is normal

 

[dirtybarry]

The seating depth I’m using (1.125) is well above the min for 9mm and any load data I’ve seen. So I doubt that would have much impact. The Bullseye doesn’t come close to filling the case so compressed loads aren’t a concern. I use a Lee FCD and only turned it about 1/4 turn after it touched the case neck. So a very light crimp in my opinion. Maybe I will lighten the crimp slightly and see if that changes things.

Thousands of rounds with the same weight bullet and COAL from very light to max loads using virtually every brand of primer available, zero issues. Currently I have my crimp die backed off to zero crimp and still no issues but the cases look nicer.