Does this 9mm brass look like over pressure ?

[lead-1]

I have been working to change my 9mm load to W231 powder but not too sure of the results so far.
I am using a LEE 356-120-TC boolit, powder coated and sized to .3565, COL of 1.060", CCI 500 primer and 4.0 grains of W231 powder.
This set up work for me using Unique but I want to try some W231 since I have 3-4 pounds of it.
Does this look to be too high on the pressure department, the top two rows are from a Ruger P85 and the bottom two rows are from a Kel-Tec? Both pistols give good groups and function great but I question the primers being pushed back into the firing pin holes but not blown flat around the edge of the primers. Opinions please.

[trails4u]

They look cratered to me......a sign of overpressure. Load doesn't seem too hot...maybe try a bit longer COAL? Can you chrony them and check velocity?

[lead-1]

I don't have a chrony and as far as feeling hot, the Kel-Tec stings a little after a few factory loads and the Ruger being full size felt fairly normal.
If I let the COL get any longer the round won't chamber reliably in the Kel-Tec, that's why I'm at that COL, it chambers in all my nines.
The area of the firing pin dent is actually a hump sticking out of the primer.
I am curious because most anytime I had any over pressured loads the primers were flattened all the way to the edge of the pocket and those were rifle loads.

[depoloni]

Not to be contrary, but that load if anything should be *low* pressure if anything relatively based on the load you're using at 4.0 grains of 231.

FWIW, lower pressure can cause mis-interpreted "overpressure" signs - instead of the primer blowing out due to high pressure, it can eject slightly and be deformed as it re-seats against the breech face. Same with cratering, can be caused by high pressure - or can also be caused by oversized firing pin holes in the breech face.

If they shot well, and accurately, I wouldn't necessarily be alarmed - I see lots of spent factory brass where the primers look about like the ones you show. Were your previously-loaded unique loads not doing the same?

[Pumpkinheaver]

The spent primers from my Ruger P-95 look exactly like yours, always have.

[Grump]

What's missing here is any reference to published loads in 9x19 with that powder. From that, what do YOU think???

Look at your breechfaces on both pistols. Pretty sure you will see the sources of the primer impressions there.

IME, the Kel-Tec pocket guns make a rounded fake "crater" with any safe 9mm load. Any pistol running more than about 23,000 PSI is capable of doing that, based on my experiences and observations with factory and safe published loads in non-Magnum handgun cartridges. I have also seen several other males of recent manufacture produce similar primer markings. Going to top safe pressures on 9mm IME will produce a change in the radius is the transition from primer face to the side that engages the wall of the primer pocket.

FWIW and you should not really believe me without some other corroborating info, my Dad and I ran 4.8-4.9 gr 231 with a 124-gr LRN and it ran just fine. Five different pistols shot perfectly with that load, and velocities were within what published sources said a full-power load would be.

YMMV. And all that.

[upnorthwis]

I'm using 4.7 gr. of WW231 with the Lee 126gr. TL in a S&W M&P. The book I have has only one load at 4.8 gr. with only 28,800 CUP. Has other powders & loads that go up to 33,400. So 4.0 seems low to me too and I get the same kind of firing pin impression.

[WHITETAIL]

The book I have right here is Hornady Handbook.
It is the 3rd ed.
9mm -124gr. Full metal jacket.
Win 231 is 3.9gr to 4.8
and 5.2 is max load:redneck:
If it were me I would be loading 4.3 at 1000fps.

[chutesnreloads]

I agree....doesn't sound like a hot load.What does spent brass from factory ammo look like?

[Calamity Jake]

Oversize firing pin holes in the breach face causes this.

[bnelson06]

Oversize firing pin holes in the breach face causes this.

My glock has primers that look like this because of the firing pin hole.

[Scharfschuetze]

The primers from my Beretta M9 (92FS) look exactly like your Ruger primers and my load is below any max load for the boolit that I use. I might add that factory and GI ball ammo primers look the same in that pistol. I'll also add that when working up a standard load for my three different 9mm handguns, the primers in the M9 always showed that flow back even with starting loads.

The primers from the same loads fired in my Browning Hi-Power look just fine with no hint of primer flow back.

Given all of that, I'd say it has something to do with the design of the pistol. As noted above, the firing pin hole is probably larger than on other designs. Manufacturers don't design their firearms to be reloaded so as far as they are concerned, once a factory round is fired it is forgotten.

[lead-1]

As listed in the original post my load is as follows, a LEE 356-120-TC boolit, powder coated and sized to .3565, COL of 1.060", CCI 500 primer and 4.0 grains of W231 powder.

My original load was from a Hornady Handbook of Reloading, 4th edition and was 5.0 grains W231 with a 124 gr. LRN bullet. In my opinion that didn't work, large group size, stung like crazy and was extra loud. That was re-researched and traded for this load in question.

This load was based on the Hodgdon Reloading website that listed a 124 gr. Berry's bullet with W231 at 3.9 to 4.4 grains. With 4.0 gr. I have good groups in two pistols, normal feeling recoil as mentioned above but the primers were the same as the hotter loads I listed.
I don't have any factory rounds fired from these pistols to compare the primer marks, but hope to remedy that sometime this week.

As for my opinion on this load, I think it works fine, but like I said I questioned the primer marks and pressure, 9mm has always been my reloading pain in the back side. I have a load that works great with Unique so maybe I will just trade my 231 locally for some of that.

[runfiverun]

just drop the 231 load a little more and see what happens.
I know 3,8 grs will reliably function my 9's. lower probably would too.
your looking at one indicator, see if it keeps doing it at a known low pressure load [heck even 2-3 rds at 3 grs wouldn't hurt anything and you'd still see if the primer craters into the pin hole]
the only other thing you can do is try another brand of primer and look for the same thing.

[lead-1]

I tried some more rounds today and they look the same as these ones. I will be lowering my loads to 3.8 grains of W231 because they worked just as well as the loads of 4.0 grains. The only thing I can figure is I didn't notice the primer markings before because I shot them from a different pistol.
Thanks everyone for the input.

[Don Fischer]

Oversize firing pin holes in the breach face causes this.

Bingo! No pressure sign I can see.

[jonp]

Bottom row, 2cd from left. I'd be pretty leery of brass that came out of my gun like that. It's a definite sign something is going on. Since the load you are using is well below max in several different manuals I'd be more inclined to first check my powder measure to make sure it was throwing correctly or better yet hand weigh several rounds and then take a look at the firing pin/hole.

Here is a question: If the handgun is using a heavy spring and the primer cup is soft then wouldn't that cause hits like this?

[dudel]

It looks like overpressure (cratered primers), but could be a number of things. The load itself isn't a high pressure load; but if your neck tension isn't tight enough, you could be getting bullet setback while the round is chambering. That could certainly cause an overpressure situation.

Try this. Load a mag, and fire a shot. Eject the next chambered round (unfired). You may want to do this for several rounds. Check the COAL of that round(s). Is it shorter? If so, you're not getting enough neck tension, and the bullet is driven back into the case while it's taking the trip up the feed ramp and into the chamber (which can increase the pressure). That can cause a number of problems, and needs to be corrected fast. If you are getting a shorter round during chambering, check the bullet for any marks (feed ramp may need polishing, or a different bullet profile may feed better).

Don't try this by manually chambering a round. The forces and dynamics are much different than firing a round.

[Shiloh]

Primers are nice and rounded. Doesn't look hot at all. Winchester online manual lists 4.4 MAX with a 124 jacketed bullet. that is at a COL of 1.15. Cratered with a lot flatter primers would be an issue.

How does it shoot?? Does it cycle, feel like hard recoil, accurate??

SHiloh

[Cherokee]

Some guns will mark the primers like that no matter what, resulting from the breech face/FP hole design. I see lots of indoor range brass with primers like that. Your load is plenty safe so don't worry about it. Wont hurt to check for bullet set back just to be sure. I load my 120 TC @ 1.055" with 4.3 gr 231 for 1150 fps; works great in several guns.

[lead-1]

I'm going to leave the loads as they are because the work, the groups are good and the recoil isn't bad at all.
Here is a picture of the uncleaned breach face, the firing pin hole looks to be perfectly round and the firing pin fits the hole fine, very little to no slop.
However the hole almost looks to be chamfered but not very uniformed at that.

[vzerone]

I'd say it's your firing pin hole.

[Scharfschuetze]

Yep, that's the culprit. I believe that you can compare your primers (post 1) to your pistol as the primer extrusions are all uniform. If used in a crime, the crime lab would have no issue in matching a case to your hand gun.