Man, I've never done THAT before.

[TriumphGT6]

Woof. What do you think, kinda hot maybe?

http://www.mv.com/ipusers/last/cases.jpg

225 gr. (14.6 gm) cast lead shoved by 7 gr. Unique. :eek: Oop...

[santa]

Neophite here, could you explain what happened in the picture please?

Thank you!

[primersinmyshoe]

It looks like the max pressure was exceeded due to an over charge of powder. Some one is reloading beyond recomended powder charge weights. What happens is that the pressure created is so great that the primer is not only flattened, the metal is blown back into the firing pin hole in the breach of the slide (aka primer flow). This appearance is about the last warning you get before the gun goes KaBoom! The primer of a safe pressure round usually has a firing pin mark that looks like a dimple, or crater, with a little lip. The circumfrence of the primer still has a radiused edge. Whe the primer starts to flatten, pressure is getting high. Now, this is for most primers. Some primers are made of a softer metal and will sometimes show false signs of high pressure. I use Winchester primers which have a harder cup (primers have two parts, the cup and the anvil, with priming compound in between. When the cup is pushed against the anvil by the firing pin the priming compound is crushed, causing an explosion, which send a jet of fire through the flash hole, igniting the powder, causing...well you get the picture). Federal and I think CCI make primers with a softer cup, which take less force to set the chain of events off. Anyone else have ideas on this subject?

[larryf1952]

Yeah, it looks like the rounds have definitely been loaded too hot. The firing pin dimples have obviously been flattened out, which is not a good sign. But, the bevel on the primers, where it fits into the case cup, don't look too bad. It may be the light and focus, but the cases in the rear of the photo look like they may be a little worse. I've seen primers on .357 and .44 Mag cases where you couldn't even distinguish a circle between the case head and the primer itself. Maybe, because of the slide action in recoil, auto cases don't have the same opportunity to get flattened as much as revolver cases. In any case, I'm glad I'm not the one loading and shooting these rounds.

[TriumphGT6]

Howdy, Santa

Primersinmyshoe is on target. The interesting thing is that the cookbook I was using (Lyman's Cast Bullet manual, as I recall) recommends 7.3 gr. of Unique as the max load for this bullet. 7.0 gr. "should" have been comfortably below that.

But every gun is different, so as they always say, approach maximum loads with caution! I had loaded 50 rounds, starting with 5 gr. of Unique & working up in steps, 5 rounds at each. Now in fact I was using Remington 2 1/2 primers, which aren't on Primersinmyshoe's list of softies. Also, I had another clue: recoil was notably harder with these loads, than with the earlier 5 loaded with 4.8 gr. of the same powder.

Other signs of excessive pressure (besides stiff recoil & flattened primers) include difficulty opening the breech, violent ejection of the empties, and bulged cases. Any decent reloading manual (every bullet or powder manufacturer publishes one, and they're not expensive) will have a long chapter on safety issues like this, with illustrations of what to look for.

[santa]

Awesome Fellows

This is why I love this forum, I learn volumes everytime I log on. Thanks to people like you guys who are not afraid to show mistakes we can all learn from.
Thanks to everyone who explained the picture, much appreciated.

[primersinmyshoe]

[QUOTE=TriumphGT6] Now in fact I was using Remington 9 1/2 primers, which aren't on Primersinmyshoe's list of softies. QUOTE]

Remington primers aren't carried in the reloading stores I frequent. Thanks for the warning.

I also frequently learn something from this forum. Thanks guys.

[larryf1952]

Triumph, I did not catch the first time around that these were rounds that you had loaded and fired...I thought that you'd found the pic on the web somewhere and were offering it up for comment. Obviously, you're an experienced reloader and know what you're doing.

I, too, have often been befuddled by contradictory load info between reloading manuals. One manual's max load may be below the minimum charge weight in another. That's the primary reason I gave up trying to extrapolate it and bought a chronograph. Between measuring velocities and watching for signs of excessive pressure, I pretty much figured out what was OK with the loads that I use.

At any rate, I'm glad you detected a problem before it was too late, and you got hurt or your gun was damaged. Stay safe! :D

[larryf1952]

Santa, glad to have you along for the ride. I've been reloading since '76, but I learn a new thing or pick up a new trick now and then from these guys, too. Lots of skilled and knowledgeable people around here, and most, like Triumph, are not afraid to ask if they suspect they're doing something out of kilter. Do you reload? Have you seen the pics of my fellow Missourian, Primersinmyshoes reloading room? It's sweet...

[neolithic hunter]

been there done that. :eek: from what i see this problem occures when you have a big case fast powder and a soft and really hot primer. this can be caused by an overload, but looks to me like a powder detonation in the case. were you loading with bullseye, 231, or lil'gun. :( i've3 had this happen with these powders now i use 700x in my auto guns, because of the fill volume per load about 80% is average. the sd from round to round is also reduced in my guns.