How flat of primer is acceptable

dwcollins · February 7, 2013, 05:45 PM

I have been searching the forums and get am a little confused about what is acceptable due to lack of pictures. Here is what my primers look like in photo 582.
9mm Spartan 1911
147g fmj
3.3 g titegroup
oal 1.155
federal primers
various brass
velocity 910fps

The other photo has my reload fired on the left and on the right is factory 115g federal fired from the same gun.
I have no problems with ejection and both seem to fit in the chamber the same and drop out easily so I know oal is ok. (factory is 1.154) my crimp is .378. So my question is (at last) Is there overpressure? Please no guesses.

**Unclenick** · February 7, 2013, 06:01 PM

Doesn't look bad. Federal primers are a bit softer than some others. CCI is harder. The pressures in that second photo could actually be the same, as a result. Typically, what you look for on the primer is cratering, which is a raised lip around the firing pin indentation that has flowed into the firing pin tunnel around the tip of the pin, and primer mushrooming, where the bottom of the primer flows out into the chamfer of the primer pocket so its fatter than the rest of the primer. Those are both signs you are at the limits for that particular primer. May still be fine for the gun, though.

oldpapps · February 7, 2013, 07:08 PM

The primers in the photos look acceptable.

Attached photo is of two cases that I have collected. NO, I did not load or shoot them. I picked them out of range pick-ups.
The one on the left is an over load!
The one on the right is a 9MM that I think was fired in a glock 40 Cal.

http://thefiringline.com/forums/atta...1&d=1360282021

Be safe,

OSOK

Rifleman1776 · February 8, 2013, 09:39 AM

Any flattening is an indication you might be approaching excessive pressure. As long as you still get easy extraction I wouldn't worry. Well....actually I would. I would drop back the charge by .1 or .2 of a grain and continue testing. Rarely is anything worthwhile by pushing to max-max pressures and velocities.

Brian Pfleuger · February 8, 2013, 09:54 AM

Federal primers flatten, crater, mushroom, even pierce, at and below starting load in my Glock 33 357sig. I've loaded Power Pistol down to starting 9mm loads in my Sig and they still flatten/pierce/crater.

Federal are probably just fine in "old school" rounds making 18 or 20,000psi but I'd consider them unsuitable for anything in the 30,000+ psi range.

oneoldsap · February 8, 2013, 04:45 PM

oldpapps , those are some ugly cases you picked up . They illustrate the reason that I never shoot on public ranges . Or even club ranges , when there are others shooting , that I don't know , and some that I do know , for that matter

chris in va · February 8, 2013, 04:58 PM

Quote:

.oldpapps , those are some ugly cases you picked up . They illustrate the reason that I never shoot on public ranges . Or even club ranges , when there are others shooting , that I don't know , and some that I do know , for that matter

Wow. You'd really hate shooting at Knob Creek then. That's too bad.

Kayser · February 8, 2013, 05:04 PM

Those look ok to me. In my view, flattened primers are not enough to indicate too much pressure. Necessary, but not sufficient.

My example is : I've been loading 357 mag for quite a while now. I always get flattened primers with it. I have tried everything to make them go away, including an experiment with a way downloaded charge. But they're always there. I never get flattened primers in any other cartridge in any other gun. So my conclusion was that it's a combo of the primers I use (Winchester) and the gun (a python) and has nothing to do with overpressure.

oldpapps · February 8, 2013, 07:16 PM

This photo is some what out of focus.
That is/was a 9MM case, the head stamp is "P-A 9MM LUGER". The primer is very flat. The typical glock rectangle with firing pin strike has flowed back. This glock must have been a newer one with a supported head.

http://thefiringline.com/forums/atta...1&d=1360368915

Be safe,

OSOK

Brian Pfleuger · February 8, 2013, 07:26 PM

That looks more like a 9mm fired in a 40SW.

oldpapps · February 8, 2013, 09:18 PM

"That looks more like a 9mm fired in a 40SW. "

Yep, the body and mouth are expanded and split to the size of a 40S&W. The web and head are in tack. But the primer is smeared and flowed back. The tel tail glock rectangle firing pin cut out.
My brother picked up this case and several others at a range just west of Lake City, or so I understand.

Be safe,

OSOK

dacaur · February 10, 2013, 04:03 AM

To gauge if I have a problem, I always compare them to factory loads shot through the same gun. My S&W bodygurad flattens ANYTHING I shoot out of it, factory, or mid range reload, doesn't matter.... I had a kel-tec PF9 that would crater everything shot out of it, factory and reload alike.... (traded it for the bodyguard)

February 7, 2013, 06:01 PM	#2
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,061	Doesn't look bad. Federal primers are a bit softer than some others. CCI is harder. The pressures in that second photo could actually be the same, as a result. Typically, what you look for on the primer is cratering, which is a raised lip around the firing pin indentation that has flowed into the firing pin tunnel around the tip of the pin, and primer mushrooming, where the bottom of the primer flows out into the chamfer of the primer pocket so its fatter than the rest of the primer. Those are both signs you are at the limits for that particular primer. May still be fine for the gun, though. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

February 8, 2013, 04:45 PM	#6
oneoldsap Senior Member Join Date: September 16, 2009 Location: I live in the foot of the Green Mountains of Vermont Posts: 1,602	oldpapps , those are some ugly cases you picked up . They illustrate the reason that I never shoot on public ranges . Or even club ranges , when there are others shooting , that I don't know , and some that I do know , for that matter __________________ Don't forget to have your liberals spayed or neutered !

February 8, 2013, 05:04 PM	#8
Kayser Senior Member Join Date: May 29, 2002 Location: Illinois :( Posts: 550	Those look ok to me. In my view, flattened primers are not enough to indicate too much pressure. Necessary, but not sufficient. My example is : I've been loading 357 mag for quite a while now. I always get flattened primers with it. I have tried everything to make them go away, including an experiment with a way downloaded charge. But they're always there. I never get flattened primers in any other cartridge in any other gun. So my conclusion was that it's a combo of the primers I use (Winchester) and the gun (a python) and has nothing to do with overpressure. __________________ ----------------- Box Of Truth Afficionado!

February 8, 2013, 07:26 PM	#10
Brian Pfleuger Moderator Emeritus Join Date: June 25, 2008 Location: Austin, CO Posts: 19,578	That looks more like a 9mm fired in a 40SW. __________________ Nobody plans to screw up their lives... ...they just don't plan not to. -Andy Stanley

February 8, 2013, 09:39 AM	#4
Rifleman1776 Senior Member Join Date: April 25, 2010 Location: Arkansas Posts: 3,309	Any flattening is an indication you *might* be approaching excessive pressure. As long as you still get easy extraction I wouldn't worry. Well....actually I would. I would drop back the charge by .1 or .2 of a grain and continue testing. Rarely is anything worthwhile by pushing to max-max pressures and velocities.

February 8, 2013, 09:54 AM	#5
Brian Pfleuger Moderator Emeritus Join Date: June 25, 2008 Location: Austin, CO Posts: 19,578	Federal primers flatten, crater, mushroom, even pierce, at and below starting load in my Glock 33 357sig. I've loaded Power Pistol down to starting 9mm loads in my Sig and they still flatten/pierce/crater. Federal are probably just fine in "old school" rounds making 18 or 20,000psi but I'd consider them unsuitable for anything in the 30,000+ psi range.

February 8, 2013, 09:18 PM	#11
oldpapps Senior Member Join Date: September 22, 2011 Location: Middle America Posts: 518	"That looks more like a 9mm fired in a 40SW. " Yep, the body and mouth are expanded and split to the size of a 40S&W. The web and head are in tack. But the primer is smeared and flowed back. The tel tail glock rectangle firing pin cut out. My brother picked up this case and several others at a range just west of Lake City, or so I understand. Be safe, OSOK

February 10, 2013, 04:03 AM	#12
dacaur Senior Member Join Date: March 16, 2010 Posts: 733	To gauge if I have a problem, I always compare them to factory loads shot through the same gun. My S&W bodygurad flattens ANYTHING I shoot out of it, factory, or mid range reload, doesn't matter.... I had a kel-tec PF9 that would crater everything shot out of it, factory and reload alike.... (traded it for the bodyguard)