What would you have told him ?

[Ben]

My friend had me look at these primers on some 30-06 cases.
He said he shot 56.0 grs. of IMR - 4831 with a 180 gr. jacketed in 30-06 brass.

I gave him my opinion about the appearance of the primers, what is yours ?

[SSGOldfart]

Back off that load was a little to hot and/or check his powder measurer see if it throwing the right charge

[303Guy]

Interesting that the primer edge hasn't flattened out. I have seen primers like that from factory loads. Eastern block or Chinese. There was no sign of excess pressure, just the indent bulged back out like in the photo.

[William Yanda]

That ring around the firing pin indent looks like the pressure is pushing the primer back into the bolt. Too much pressure.

[Ben]

This is interesting, keep your replies coming...............Here is what the Speer loading manual says about his charge of 56.0 grs. of IMR 4831.

180 Speer RNSP, Spitz BTSP, Spitz SP, MT SP or GS SP IMR IMR-4831 55.0 2544
Remarks: start charge

180 Speer RNSP, Spitz BTSP, Spitz SP, MT SP or GS SP IMR IMR-4831 59.0 2684
Remarks: max charge; compressed load

[oneokie]

Overly large firing pin hole in the bolt. Or soft primer cups.

[longbow]

Yes, I noticed the same thing. Any time I have reached somewhat high pressure the primer flattens out noticeably. These have what appear to be nice round edges.

Without looking up the load data I have no idea if it is too heavy a powder charge but I would say yes with primer dents extruding back into the bolt after the firing pin. Odd that they didn't flatten more though.

Primer make?

Longbow

[ubetcha]

Overly large firing pin hole in the bolt. Or soft primer cups.

My thoughts also. The edges of the primers do not look flattened due to over pressure.

[44man]

Weak Pin spring. Primer pressure is pushing the firing pin back.

[MtGun44]

Bolt hole for firing pin is oversized, most likely. I would have to compare to factory
ammo to be certain, but seems extremely unlikely that there is a pressure issue due
to the nice, rounded edges on the primers.

Bill

[jonp]

Odd that it didn't flatten. I agree with other comments. I think the primers are soft. I'd still back off the powder a grain or two and compare. I had something like this with pistol primers not long ago. Well under max but enough of a crater that the cylinder would not turn

[runfiverun]

The primers flowed into the bushing area around the firing pin.
Shrug

[dubber123]

Overly large firing pin hole in the bolt. Or soft primer cups.

I give Nolan the gold star. No flattened edges, either small pin tip or too large of a firing pin hole.

[KYCaster]

Hodgdon site says 180 gr. Sierra SPBT.......56.8 gr. IMR4831 is max.

Looks like too much room around the firing pin......needs a bushing.

Looks like location of the firing pin strike is inconsistent....some centered, some not. Sloppy chamber?

Not a very deep firing pin hit....short firing pin or VERY SOFT primer?

More details on the gun and load?

Jerry

[Lefty bullseye shooter]

In my experience first sign of pressure is flattened primer THEN more pressure is flattened primer and crater around firing pin indent. With signs of high pressure the crater is very sharp edged not rounded like the picture. I would go with oversized firing pin hole also.

Scott

[bhn22]

Weak Pin spring. Primer pressure is pushing the firing pin back.

Me too! I'd also check the firing pin hole & pin protrusion, just to be thorough.

[sirgknight]

Algebra problem with visual results....first of all I looked up the load data at Hodgdon for the 180gr bullet over IMR4831. It shows max load at 56.8gr, compressed. The primers, to me, indicate that he is "right there".

[Ben]

Truth is other reloads that were safe gave the same primer appearance. Rifle is an old ( Mid 70's ) Remington Model 760, pump, 30-06.

I told my friend that the firing pin hole was too large.

He said the loads were accurate, they ejected well from the rifle.

I told him he might try a different primer. The primers might be a bit soft ? Yes, he might drop 1 - 2 grs. of propellant, but the edges of the primers don't seem to indicate high pressure ? ?

Ben

[wv109323]

I would examine the primers and the rifle bolt. Something strange is going on. The bottom most cartridge has a larger diameter raised portion than the others. It also appears that some of the primer strikes are off center more than others.
I would try another brand primer with the same load.

[castalott]

Alright, I'll make a fool of myself....2 of the primer strikes are centered and 2 are way off. That is a really big chamber or some strange brass. Decap them and see if the primer holes are drilled out a little. I've read about something like this with auto loading rifles where the firing pin floats back and forth in the ejection cycle to strike the primer twice. So I'm guessing very soft primers in an autoloader where the firing pin impacts the hammer....YMMV...lol PS... were the cases sooty? Like the powder wasn't burning right? Ok..I admit it...I don't know what I am talking about