Overpressure signs?

[PNW_Steve]

Hey Everyone,

With the current primer situation I find myself with only magnum small pistol primers to load with.

Some poking around on the Internet I found multiple instances of people recommending a 10% reduction in powder charge when submitting magnum primers.

I had been running 5.0gr of SW Auto Pistol behind a 147gr coated bullet.

I dropped the charge to 4.5gr and tried it out. I am seeing primer deformation that is quite different than what I have seen in the past. If it went all of the way around I would call it "crateting". But it is just on the sides.

I have never seen anything quite like this.

What do you all think?

Thanks
S.

[fredj338]

Well 10% reduction is a bit enveloping. I have found mag primers don't affect vel/pressures much with faster powders at midrange. Slower powders though will show a greater vel thus pressures. So 10%, no. In say 9mm or 45acp using WST @ midrange levels, less than 15fps gain vs std primers. Now going to a mag primer in my 357sig with full power AA#9, almost 100fps higher, quite a bit.

[PNW_Steve]

I have been trying to upload pictures for 20 minutes. It keeps failing. I'll try again later.

[starnbar]

No doesn't look like overpressure the primers are still retaing the round edge which is one of the first things to flatten and fill the pocket

[sigep1764]

It looks like you fired those in a Glock. Same as my brass looks after it's been fired.glock has that weird firing pin and pin hole in the breech. Like I said, looks normal.

[charlie b]

^^ditto

[PNW_Steve]

It looks like you fired those in a Glock. Same as my brass looks after it's been fired.glock has that weird firing pin and pin hole in the breech. Like I said, looks normal.

Give the man a Cupie Doll!!

This is my first Glock and my first trip to the range with it.

I did note that the primers were not flattened and that is part of what confused me. the raised portion to each side resembles primers that I have seen indication over pressure. Only, they showed flattening and a raised area surrounding the primer strike like a "crater".

This one confused me :)

[Conditor22]

*** pictures need to be under 200 kb to upload :)

[BigAlofPa.]

I loaded some 9mm with a middle of the road load. Using small rifle. And sport pistol. Just doing an experiment with these.

[sigep1764]

Give the man a Cupie Doll!!

This is my first Glock and my first trip to the range with it.

I did note that the primers were not flattened and that is part of what confused me. the raised portion to each side resembles primers that I have seen indication over pressure. Only, they showed flattening and a raised area surrounding the primer strike like a "crater".

This one confused me :)

Dude, had to look up a Kewpie Doll. They're gonna give me nightmares now.

[dtknowles]

I have a box of my Dad's stuff from his time in basic training before he to fight in WWII. There is a Kewpie Doll, a unit flag and a very racist map among some pictures etc.

Tim

[PNW_Steve]

I have found that the loads that I was concerned about run fine in my Walther PPS and my 9mm AR (16") with no overpressure signs. My new Glock continues to put it's freek mark on the primers.... And the Glock is the only one that has trouble feeding them.

They are 147gr FP loaded to 1.160"COAL . I am going to try loading some to 1.150" and see how that plays with the Glock.