Cratered 9mm primers

[Zendude]

From all I've read, primers are not the most reliable way to tell if loads are too heavy unless they show some really extreme damage. I loaded some 9mm with S&B primers, 124 grain plated bullets over 4.3 grains of Universal, 1.135 OAL, and am getting cratered primers. I know 9mm is naturally a relatively high pressure cartridge, but are slightly cratered primers fairly normal? The feel of this load and the soot on the brass indicates that this is a light load rather than a near max load.

 

[Walkalong]

What does the book say about that load? Universal is good stuff but can be peaky when it gets near the top. Looks like a poor firing pin to firing pin hole fit as well.

 

[Zendude]

What does the book say about that load? Universal is good stuff but can be peaky when it gets near the top. Looks like a poor firing pin to firing pin hole fit as well.

The published load data is a bit inconsistent. Hodgdon shows 4.4 as max for a Berrys 124 grain hollow base round nose .356 dia plated. The max for a 125 grain .355 FMJ is 4.9 grains. Hornady lists a max of 5.2 for a 124 grain .355 FMJ. The FMJ loads also list a shorter OAL than what I'm using. I am loading a .355 124 grain Xtreme plated (heavy plated).

 

[RecoilRob]

I don't see any worries with those primers...just a generous firing pin hole. The edges are still rounded and I bet factory ammo looks the same or much worse in that gun.

 

[wally]

I'd compare these to primers from factory ammo fired in the same gun. Often this is caused by the gun (as was said, over sized firing pin hole) and not the ammo.

 

[Walkalong]

The published load data is a bit inconsistent. Hodgdon shows 4.4 as max for a Berrys 124 grain hollow base round nose .356 dia plated. The max for a 125 grain .355 FMJ is 4.9 grains. Hornady lists a max of 5.2 for a 124 grain .355 FMJ. The FMJ loads also list a shorter OAL than what I'm using. I am loading a .355 124 grain Xtreme plated (heavy plated).

That definitely seems inconsistent. I guess the OALs vary a good bit. Just looked at the Hodgdon online data and it is indeed a bit confusing. Just goes to show you we can't guess at it. I would think 4.3 would be more than OK as far as pressure goes.

 

[243winxb]

I'd compare these to primers from factory ammo fired in the same gun. Often this is caused by the gun (as was said, over sized firing pin hole) and not the ammo.

If factory does not look the same, reduce powder charge.

 

[RugerOldArmy]

Looks like a poor firing pin to firing pin hole fit as well.

That is my take, too.

 

[ArchAngelCD]

Just be careful not to shorten the COAL because small changes in case capacity in the 9mm will increase pressure, sometimes greatly.

 

[higgite]

FWIW, the Beretta 92FS that I lost in a horrible boating accident does did that with my reloads and with factory ammo.

 

[LiveLife]

are slightly cratered primers fairly normal?

Do you get cratered primers with other loads, particularly lighter loads?

Looks like a poor firing pin to firing pin hole fit as well.

I get top row primer indents from Just Right carbine. Bottom row is from Glock - notice light to deep primer indent from different powder charges.

 

[SC_Dave]

Are S&B primers softer than others? I've never used them before.

 

[Laphroaig]

FWIW, the Beretta 92FS that I lost in a horrible boating accident does did that with my reloads and with factory ammo.

Ditto with my 92FS. Very distinctive and unusual firing pin strike. I can pick my brass out from others very easily.

 

[Zendude]

I running the ammo through a new pistol (Ruger American compact), so I am not sure if it does the same to factory ammo primers. I didn't pay attention to the factory cases I ran through it on the range trip previous to my last one. I'll run some factory ammo through it tomorrow and see what they look like.

 

[LiveLife]

The published load data is a bit inconsistent. Hodgdon shows 4.4 as max for a Berrys 124 grain hollow base round nose .356 dia plated. The max for a 125 grain .355 FMJ is 4.9 grains. Hornady lists a max of 5.2 for a 124 grain .355 FMJ. The FMJ loads also list a shorter OAL than what I'm using. I am loading a .355 124 grain Xtreme plated (heavy plated) ... 1.135 OAL

That definitely seems inconsistent. I guess the OALs vary a good bit. Just looked at the Hodgdon online data and it is indeed a bit confusing. Just goes to show you we can't guess at it. I would think 4.3 would be more than OK as far as pressure goes.

I think the key factors are sizing of the bullet and te

Hodgdon listed larger .356" sized Berry's 124 gr HBRN at 1.150" with 4.4 gr as max charge but 4.9 gr for .355" sized Sierra 125 gr FMJ at shorter 1.090"

Since you are using .355" sized X-Treme RN HPCB (Heavy Plate Concave Base), you can reference 4.4 gr max charge for Berry's HBRN-TP (Hollow Base Round Nose - Thick Plate) or use a chrono and reference 4.9 gr max for Sierra 125 gr FMJ, especially since you are using longer 1.135" than published 1.090" OAL.

 

[Zendude]

Are S&B primers softer than others? I've never used them before.

S&Bs are similar to Winchester regarding how hard they are. The S&B primers are much more flat than Win or CCI, which makes them work better in my Lee 1000 primer feeder.

 

[Zendude]

I think the key factor is the sizing of the bullet.

Hodgdon listed larger .356" sized Berry's 124 gr HBRN at 1.150" with 4.4 gr as max charge but 4.9 gr for .355" sized Sierra 125 gr FMJ at shorter 1.090"

Since you are using .355" sized X-Treme RN HPCB (Heavy Plate Concave Base), you can reference 4.4 gr max charge for Berry's HBRN-TP (Hollow Base Round Nose - Thick Plate) or use a chrono and reference 4.9 gr max for Sierra 125 gr FMJ, especially since you are using longer 1.135" than published 1.090" OAL.

The Berrys load data why I was hesitant to load more than 4.3 gr. Unfortunately I don't have a chrono or a place to use it if I did. When I used an OAL of 1.150 to match the Berry load, it would not always cycle the slide. The Berrys bullet is a bit longer than the Xtreme I am using, so I figured I could reduce the OAL slightly. It did work- no more FTE, but I wanted to check the cases to see if I reduced the OAL too much. I have heard that a .03 reduction in 9mm can double the peak pressure, which makes me a lot more nervous about reloading 9mm than 38s.

 

[LiveLife]

I do not believe you are at over pressure with 4.3 gr at 1.135" OAL because you are using smaller .355" sized X-Treme bullet when published max of 4.4 gr at 1.150" OAL is with .356" sized Berry's bullet.

IIRC I loaded Universal for USPSA with 4.3-4.4 gr and 124 gr FMJ for 130 minor power factor and Glock 17.

 

[Zendude]

Just be careful not to shorten the COAL because small changes in case capacity in the 9mm will increase pressure, sometimes greatly.

That's what makes me nervous about 9mm load data where I don't know the exact length of the bullet used. I start my charge workup low but don't have a chrono to check velocity.

 

[LiveLife]

Without a chrono, you can do this when using shorter than published OAL/COL:

- Determine the max OAL that will fully chamber in your barrel - https://www.thehighroad.org/index.p...rel-find-a-max-o-a-l-with-your-bullet.506678/

- Then identify the working OAL that will reliably feed/chamber from the magazine - https://www.thehighroad.org/index.p...l-with-your-bullet.506678/page-2#post-8864541

- If working OAL is significantly shorter than published, subtract .2-.3 gr from published start/max charges

- Calculate so your new max charge won't be compressed by working OAL bullet seating depth - https://www.thehighroad.org/index.p...g-depth-and-rmr-124-jhp.821665/#post-10555695

- Work up from new start charge until you have reliable slide cycling and spent case extraction/ejection (I usually use .2-.3 gr powder charge increments)

- Then continue work up in .1 gr increment towards new max charge until you have accuracy trend

 

[Vern Humphrey]

What does the book say about that load? Universal is good stuff but can be peaky when it gets near the top. Looks like a poor firing pin to firing pin hole fit as well.

That's exactly what I would look for. Pistols in general do not produce near enough pressure to produce the "pressure signs" seen in rifle cartridges. You would have to generate about twice the max pressure for a 9mm to get those primers to crater from pressure.

 

[Steve C]

I have owned this Taurus 92 for over 25 years and it has always left cratered looking primers on all rounds fired through it. The reason it does this is because of the overly relieved firing pin channel shown in the 3rd picture of the bolt face. It isn't a problem as all rounds fire and eject reliably. If you have the same cratering on factory ammo its probably a characteristic of the gun caused by a similar condition to this one.

 

[ArchAngelCD]

That's what makes me nervous about 9mm load data where I don't know the exact length of the bullet used. I start my charge workup low but don't have a chrono to check velocity.

The information "bds" supplied should put your fears to rest. My warning wasn't to cause anxiety, just a heads up that pressures can climb quickly in small high pressure cases like the 9mm.

 

[Robert101]

I don't see cratered primers in the original post nor do I see flattened primer edges. To me, there is not evidence of an over pressure condition shown by those cases. Also, I'm not a fan of reading primers as a sole indication of pressure. Measure the case heads before and after for firing expansion and compare. Also see if the fired cases will insert back into the chamber from which they were fired. I've been lucky as my guns don't seem to reach an over pressure when adhering to published data - at least I don't think so - in the absence of a pressure gage.

 

[Galil5.56]

This is from back around 2000, quoted from a factory tour of Beretta USA. BTW, and FWIW, it was also mentioned that USA made 92's, had fewer defect rates than Italy.

The firing pin hole on a Beretta is chamfered. This reduces the possibility that a bad or burred case will bind on the breechface, causing a jam. It also aids proper feeding when a primer is not properly fitted flush to the cartridge head. Beretta polishes their breechfaces to make feeding more reliable. One of the students in our class was a firearms examiner for a state police agency, and he commented that matching brass cases from a Beretta was extremely difficult because they left no unique breechface marks due to this polishing.