Here is some brass fired out of my RRA AR-15. They have the infamous dangerous pressure indicator of ejector smear, but that is all. No primer flattening, no other pressure signs. The gun leaves a little shiny spot on LC brass, but this HSM brass is showing alot more. Is it possible I do not have a dangerous pressure issue, but rather the brass is softer, or I have a sharp edge on my ejector? My Colt AR-15 shows no signs at all with the same rounds

I am not blackrifle guy, so this may be worthless, but I wouldn't shoot that load again.

jeffe

I would look at both the level of the load, is it beyond max and the ejector hole/spring/plunger?

In a gaspoerated rifle one should take care not to exceed max pressures...

They tend to break.

Best regards Chris

quote:

Originally posted by FURocious:
Here is some brass fired out of my RRA AR-15. They have the infamous dangerous pressure indicator of ejector smear, but that is all. No primer flattening, no other pressure signs. The gun leaves a little shiny spot on LC brass, but this HSM brass is showing alot more. Is it possible I do not have a dangerous pressure issue, but rather the brass is softer, or I have a sharp edge on my ejector? My Colt AR-15 shows no signs at all with the same rounds

Any head expansion? Loose primer pockets? A load that look's that hot should give both. Have you tried the same load in a different case? Is this near or at max? I've never heard of HSM cases but I tried some old Herter cases in 25-06 that did the same thing with safe loads. Well safe for other cases! I quit using Herter cases.

What brand of primer's are those? That bad an ejector mark I'd think the primer would flatten. By the way, I've never loaded for auto-loaders.

My bet is that they aren't that bad, the primer is quite rounded, not flat at all. I'd say soft poor brass. I wouldn't however, bet my life on it, it's just not a good idea to shoot any ammo that shows any of the traditional pressure signs, caase head expansion, loose primer pockets, brass extrusion into the ejector slot, etc. There is no way to know, so the best thing to do is use some other ammo.

if those came out of my rifle, I'd treat it as a giant waving red flag.

Try letting the action cycle a round into battery but don't fire it. Just let the action slam it into place. Remove the cartridge and examine it. If you have a raised edge around the ejector hole you might already see beginning sign of it on unfired brass if the headspace is tight enough to support the case.

quote:

Originally posted by jstevens:
My bet is that they aren't that bad, the primer is quite rounded, not flat at all. I'd say soft poor brass. I wouldn't however, bet my life on it, it's just not a good idea to shoot any ammo that shows any of the traditional pressure signs, caase head expansion, loose primer pockets, brass extrusion into the ejector slot, etc. There is no way to know, so the best thing to do is use some other ammo.

This situation crops up from time to time and, for me anyway, it has always been soft brass.

Test the same load in different brass and, or the same brass with a known safe load in the same rifle. roger

AR's will do that with factory civilian brass quite often. Is this HSM manufactured loads or your handloads?

I've seen some Federal brass that was so soft that the primers fell out after the second loading, and the load wasn't too hot, just buttery brass. But the neat thing about AR-15s is they take a licking and keep on ticking.

It doesn't make any difference what the pressure of the load was; it was too much for that brass. I agree that it aappears to be soft brass. In that instance, you load to the brass, not to the pressure capabilities of the cartridge or the gun.

When I was working with the 416 Remington, component brass from Remington was not available. I purchased Bell/Mast brass for testing purposes. That brass was considerably softer than the Remington brass that the factory loads were loaded in. The factory loads generated 65,000psi which is normal for that cartridge. The Remington brass that the factory loads came in had no problems with that pressure level. The Bell/Mast brass could not be loaded anywhere near that pressure. Anything over 56,000psi would show distinct ejector marks, just like you are seeing.

You load to the cartridge/rifle specs UNLESS the brass tells you that you can't. If you don't pay attention to what the brass is telling you, at best, case life will be short, but things could get worse than just that.

quote:

Originally posted by NFMike:
It doesn't make any difference what the pressure of the load was; it was too much for that brass. I agree that it aappears to be soft brass. In that instance, you load to the brass, not to the pressure capabilities of the cartridge or the gun.

Robots can't add spice to taste.

OK, I have a little more info on this matter.

These rounds were loaded using all new components by Hunting Shack Munitions (HSM) out of MT. These are the high velocity 75gr tactical loads offered by that company. I called and talked to the company manager and was told they worked directly with Hodgdon on the recipe for this round and sell hundreds of thousands of this type loading to LE and Civ customers.

I posted this same thread on AR15.com and got some interesting feedback and learned a few things about carbine type AR-15s. One of those lessons was that carbines are harder on brass than rifle lengthed AR-15s because of the gas pressure differences and timing. Because the timing of a carbine is faster with increased gas pressure the brass gets beat up.

This is the first carbne I have loaded for, so naturally like some of you I saw a red flag with the ejector smear with this load. But with the lack of other pressure signs (totality of circumstances) I tend to agree with my Ar-15.com friends when they say the brass looks OK. Some say all their brass coming out of their carbines look the same as my pictures posted here.

So, I will tread carefully and have HSM use 5.56 brass (with the thicker webs) for these loads.

I'll agree with Mike, the pressure probably is within specs, which Hodgon helped them with. The problem is that the brass is not and is the limiting factor. If it blows a primer it matters not whether it is 50000 psi or 70000, the result is the same. I would say the pressure is safe, their brass is junk, which makes the pressure not safe. I would be more than hugely surprised if it makes a bit of difference whether it's a carbine, or a 700 Rem for that matter, how the bolt cycles can't have anything to do with brass flow into the ejector slot. That mark is not brass getting physically beat up, it's from brass flow under pressure.

quote:

That mark is not brass getting physically beat up, it's from brass flow under pressure.

roger

I've shot Federal American Eagle ball in my AR-15s that had plunger marks like that. My guess is that the brass is soft.

Does it do the same thing with other ammo?

Quite frankly, it DOES NOT look like excessive pressure to me, as there is no deformation of the primer cup AT ALL, just an ejector mark. No smearing of the headstamp either. I suspect the culprit is an ejector plunger that is too long, or that is protruding slightly from the bolt face for some reason-like a dirty ejector channel.

IF new primers require about the right the force to seat them (ie., the pockets have not expanded), I would not be hesitant to use that ammo. Try some in a strong bolt action like a Rem. 700 and see what the case-heads look like....