9mm cratering?

[Jon Road King]

So I tried some 9mm for the first time and ran through some Unique and Bullseye loads yesterday in my Beretta PX4. I loaded up 4 different charges of each with 124 gr X-treme bullets. Unique was 5.3-5.6 with a 0.1gr step and the Bullseye was 4.1-4.4 with the same 0.1gr step.

Both powders gave me what looks like cratering primers on the first two steps, so I didn't even test fire the last steps. But today a buddy and I went shooting with just factory ammo and as I was scrounging up brass I noticed that the factory ammo from both guns (we both have PX4's) showed the same exact signs of cratering I was seeing from my reloads.

The pics below show one of my two steps and the 3 cases outside the box are factory ammo rounds. All of the cases show what looks like cratered primers.

Do Berettas give the same kind of weird primer mark as Glocks? Am I actually looking at cratered primers or is this normal just normal for these guns?

[J-cat]

If you look at your breech face you'll understand why these primers cratered.

[Kappy]

Maybe headspacing? But for it to be happening in two different guns... that's weird.

[Intimid8tor]

I run my unique loads a bit lighter than that. I tend to go up to 5.1 grains, but sometimes load at 4.9.

[Kappy]

A bit of research... apparently Beretta puts a chamfer around the firing pin. I have no idea why they would do that... but there you go!

[reckoner]

That seems hot for Unique. The Hornady manual lists a max charge of 5.0gr for 124gr FMJ RN.

[Jon Road King]

If you look at your breech face you'll understand why these primers cratered.

Wow, when I first looked at the breech, I didn't notice anything. Only when I put it side by side with my 1911 did I see the difference. Yup, Kappy is right. There sure is a chamfer there. The Colt has crisp and sharp hole, but the Beretta has a rolled end to the hole.

So how the hell are you supposed to tell the difference between a stock crater and a real high pressure sign crater?

[Jon Road King]

That seems hot for Unique. The Hornady manual lists a max charge of 5.0gr for 124gr FMJ RN.

X-treme actually recommends the Speer manual for TMJ (5.2-5.8)

[BigBronco]

They look fine to me. The edges of the primers are still curved. Pressure issues will show up as flattened edges before true cratering.

[J-cat]

Wow, when I first looked at the breech, I didn't notice anything. Only when I put it side by side with my 1911 did I see the difference. Yup, Kappy is right. There sure is a chamfer there. The Colt has crisp and sharp hole, but the Beretta has a rolled end to the hole.

So how the hell are you supposed to tell the difference between a stock crater and a real high pressure sign crater?

Measure case expansion instead.

[Jon Road King]

Thanks guys, good to know

[dung8604]

Measure case expansion instead.

Link on how to measure case expansion?

Sent from my Nexus 4 using Tapatalk

[J-cat]

You don't need a link.

Measure case expansion at the widest point and compare it to factory ammo.

[stilly]

Hey! How does that PX-4 shoot? You like it? It has the rotating bolt/barrel right?

I will look at one in the morning and see what the bolt face looks like...

[Jon Road King]

Hey! How does that PX-4 shoot? You like it? It has the rotating bolt/barrel right?

I will look at one in the morning and see what the bolt face looks like...

Personally I love it. I bought it years ago when they first came out and my buddy liked shooting mine so much that he picked up one also. Same trigger action as the my 92 so going back and forth between those is easy, but after shooting my crisp-like-glass 1911 for a while, I have to re-acquaint to the the trigger pull lol. Take down and cleaning is quick and simple too.

But it shoots like a dream. Shoots flat as hell, even with a shorter barrel than the 92 (rotating barrel is awesome... it actually only does about a quarter turn but you can tell a difference between it and the 92). When I ran through my test rounds, I used a laser on the rail for the first time (at 25'), and it was shooting tight as hell with that laser (with a laser I could practically duck under the table on the first couple rounds and still hold it on target, LOL!).

On Sunday we were tagging a 11x17 metal plate at 150 yards for fun.... and I was hitting it just as often with my PX4 as with my 1911.

Probably my only complaint is that the mags from the PX4 and the 92 are damn near identical. The 92's base is just slightly narrower, but the mags both have the same shape, so it's easy to confuse the two when they are stacked together in my safe. I have learned to separate them, heh.

Fun little gun though. Sleek and simple.