Weird Looking Primers??

[corey006]

WARNING, load data used here is above current reloading manuals, use at your own risk. Neither the High Road or the authour advises using this load.

Load:

10mm Auto(of course)
Starline Brass (NEW)
CCI 350 Mag
200gr XTP
IMR [email protected](trickled each individual charge) and yes scale is 100% accurate.
1.260 OAL

S&W 1006
Wolf 22lb Recoil Spring

I have shot this load before in my 1006 but NEVER noticed the brass coming out like this.

I shot 50 rounds and about 1/2 came out like this. No malfunctions of any kind and accuracy was fantastic.

I de-primed a couple of the suspect cases and everything on them looked normal. There was no black smoke around the primer and primer was not pierced.

It almost seems that upon ejection the anvil is striking the inside of the primer and pushing back on it as it strikes the breech face?

If you look closely at the pic you can see that around the firing pin indent there is brass colour. I am assuming the plating on the primer came off?

The only thing that may have happened is I was using a RCBS hand-priming tool and sometimes I squeeze a little too hard and it seats the primers a little too deep...?...I think I may have just answered my own question.

 

[BruceB]

I'd say your pressures are very high, even though you say you've used the load before.

What is probably happening is that the primers are extruding under pressure back into the firing-pin hole in the breechface, and then as the barrel drops into the unlocked position, the extrusion is being sheared off by the edge of the firing pin hole.

I would drop the charge weight some considerable amount, perhaps at least one full grain, and refire to see what the primers look like.

I had a very similar occurrence in a P95 Ruger 9mm, with a load that four other 9mm guns accepted happily. About five rounds in the Ruger, and the sheared-off primer metal would build up inside the breechface and stop the firing pin from contacting the primer for the next shot. The primers of the rounds fired in the Ruger looked just like yours.

This surely looks like a high-pressure (TOO high-pressure) situation, and the easy way to check that is just lower the charge and fire a few for comparison.

Be careful.....

 

[frogomatic]

I could be mistaken, but it appears that your cases have crimped primer pockets. I'm no expert, but that might have somthign to do with it. If I'm wrong, somone please correct me.

 

[BruceB]

frogomatic, pard;

Crimped primer pockets are normally used to PREVENT primers from backing out in automatic weapons, for military applications, in other words.

Starline cases (as illustrated) are commercial items, and do not have crimped pockets. Such crimps are applied AFTER the primers are seated in the case.

So....you're wrong (grin). That's an interesting 'handle' you have. Care to tell us its origin???? I keep thinking about the old "frog-in-a-blender" joke.

 

[The Bushmaster]

THAT is an "over pressure" sign!!! Back off on the amount of powder before you cause undue stress on your gun and have a KA-BOOM!!!

 

[JoeHatley]

The IMR site shows 7.8 grains as MAX for that powder/bullet combo. Your 9.6 grains is 23% over max.

May want to re-evaluate your load data.

Good Luck...

Joe

 

[corey006]

There is NO denying it is a HOT load...hence the WARNING at the top of the page?

I do plan on backing off on the charge...

Like I said before...I have never seen or heard of primers doing this?

I usually look for severly flattened primers, cratered primers, gas leakage around primers.



I have shot this same exact load out of the same pistol...and the primers did not look like this?

It is a HOT load but within SAAMI max for the 10mm Auto.

McNett(DoubleTap Ammo) has done extensive pressure testing with G20 with both KKM and Factory barreled Glocks and has gone as high as 10 gr of IMR 800-X with 200gr bullets.


I have shot as high as 9.8 gr of IMR 800-X in my Witness 10mm with no problems.


Joe,

I am aware of IMR's book data for 200gr and 7.8 gr of IMR 800-X...

The DATA I am using comes from Glock Talk.

http://glocktalk.com/showthread.php?threadid=179348&perpage=25&highlight=&pagenumber=1


There are guys there shooting the EXACT same loading out of FACTORY Glocks, only at 10.0 gr of IMR 800-X....

Your better get over there and save them from themselves getting hurt

 

[wally]

If you gun doesn't crater the primers of factory ammo or other of your reloads, I'd consider it prudent to back off.

--wally.

 

[The Bushmaster]

Flattened Primers Are Not A Sign Of Over Presure...!!!:banghead:

 

[The Bushmaster]

DOUBLE ENTRY (sorry)