Case head blowouts

[Jupiter7]

AR15's can not fire out of battery. Bolt has to be completely locked before the hammer can reach the firing pin.

One more thing, how was this brass cleaned? Brasso??

"kinda" is the key word.
Fwiw, I've used brasso on every piece of brass I've ever reloaded, all of them. I've never inside reamed converted 300blk brass. I have "brown" LC brass from 79' that is on it's 8th loading as 300Blk. I don't convert foreign stuff, for the thick neck issues. I think there's a lot of maybe's being thrown around. Simple fact is that Phoenix said he's trimming his brass to 1.553, 300blk max trim is 1.368, I believe. Until he confirms his dimensions, it's the easiest answer. I've got 9 AR's(2 in 300blk) pretty familiar with them at this point.

[WILCO]

This was all LC brass. I got 200 rounds of LC rounds when I bought an AR from a friend, He didnt reload I also bought 2000 FC XM193 from him that were sealed in their factory boxes. After firing 60 of them I had several head failures so I asked him about it. I got the "Oh yeah sorry those were loaded real hot by a friend of mine.

So you're saying you've had multiple case failures with a firearm and haven't checked the head spacing yet? You're making your own brass too? And your having issues with the process? You're also substituting reloading components from specified data? You're loading to near max charges? I've gotta tell you buddy, there are too many things wrong with your situation and until you're willing to do the basics, you're just going to go in circles. Case failure is as old as metallic cartridge reloading itself. The causes are basic principles of reloading. My best advice is to stop what you're doing and go back to square one. Otherwise, we'll be reading your thread of "My gun blew up and I lost an eye and two fingers!" followed by a "How do I thank my girlfriend for all the typing she's done in a gun forum?" thread.

[Phoenix]

I had a true case head separation in 300blk, second round fired in new barrel. Mine was a chamber issue, checking headspace would have saved me a lot of trouble. The other half stayed in the barrel, ejected piece looked like a jagged piece of 9mm brass.

Can we see pictures of the neck/shoulder end of the brass?

Also, did you mess up you case trim length measurements in the original post? Trimming 1.558 would definitely cause this case blowout issue, kinda like firing outta battery. That'd be about 2/10" over the 1.358 I trim to. If so, problem solved.

typo 1.358. corrected

all cases were within .001 of each other. And all 10 were dropped in the chamber and the bolt closed with finger pressure.

[Phoenix]

AR15's can not fire out of battery. Bolt has to be completely locked before the hammer can reach the firing pin.

One more thing, how was this brass cleaned? Brasso??

Bolt was completely closed. Most of this I loaded one at a time and verified the bolt was closed. It will close with light finger pressure.

SS tumbled in water, dawn, 1/4 teaspoon lemmishine.

[Jupiter7]

Phoenix,

The bullet your using is the plain based hornady 150gr soft point? Also, what other powders might you have that are commonly used in 300blk, ie...h110, lil gun, 5744, RL7, w296? It may be time to start ruling out common denominators. And try a different load. I found that the hornady data isn't really pushing things. Pretty much same charges of powder with greater OAL. I load the same bullet and it's been a solid shooter.

I sent ya a PM.

[Phoenix]

So you're saying you've had multiple case failures with a firearm and haven't checked the head spacing yet? You're making your own brass too? And your having issues with the process? You're also substituting reloading components from specified data? You're loading to near max charges? I've gotta tell you buddy, there are too many things wrong with your situation and until you're willing to do the basics, you're just going to go in circles. Case failure is as old as metallic cartridge reloading itself. The causes are basic principles of reloading. My best advice is to stop what you're doing and go back to square one. Otherwise, we'll be reading your thread of "My gun blew up and I lost an eye and two fingers!" followed by a "How do I thank my girlfriend for all the typing she's done in a gun forum?" thread.

None of the above!

Checked the head spacing in multiple ways before ever firing to begin with. Then after this happened Checked with go/no-go (and checked the other 2 uppers the shop had, all good)

No issues with the process, dont recall saying that.

The only thing you could call a substitution would be the primer, I dont use Winchester primers, only CCI. I have read over 100 pages of others experiences I am not the only one using CCI #41. The bullet and powder are in hornady #9, My initial statement about the primer was a question not a statement. (most of others experiences were than below 18 the gun didnt cycle properly.

Not near max charge. 19gr is right in the middle. 22gr is the listed max load. The manual has only a 6gr spread

Been reloading for 10 years and am very meticulous about everything involved. Reading all the info and asking questions makes much more sense than assuming allot and making negative comments. Have reloaded 10s of thousands of rounds with never and issue until this. Comments like this make people want to not ask questions which is not what this forum is about.

[Phoenix]

Phoenix,

The bullet your using is the plain based hornady 150gr soft point? Also, what other powders might you have that are commonly used in 300blk, ie...h110, lil gun, 5744, RL7, w296? It may be time to start ruling out common denominators. And try a different load. I found that the hornady data isn't really pushing things. Pretty much same charges of powder with greater OAL. I load the same bullet and it's been a solid shooter.

I sent ya a PM.

I have almost everything, H110, W296, IMR4227, no lilgun

Yes it is the plain based 150gr sp.

[Phoenix]

I pulled 5 pieces of factory brass and compared dims with SAAMI data. The funny thing is the trim lengths varied quite a bit. all over the range, 1.356 - 1.368 Even the case weights had a 5gr spread. My cases were all within 1gr of each other.

Tore down and loaded the factory cases even changed the primers.

After checking 5 different brands of 223 brass the brand with the most consistency was PMC (only 1/2gr variance) so I converted 10 PMC cases and loaded them at varying charge weights. Shooting later today. Will use the chrony also this time.

Personally I believe this was a brass issue. I put the previous LC brass in the scrap bucket.

[xacex]

Could have got a few pieces of that brass the government is now deciding to destroy with an annealing machine. Some sellers are unaware that brass from government liquidations for scrap can be put through a machine that will make the brass unusable. Even SAW brass can be weakened if sustained full auto got the gun hot enough to cook of a few rounds from what I read on the interweb. Its on the internet so it has to be true.

[Phoenix]

Could have got a few pieces of that brass the government is now deciding to destroy with an annealing machine. Some sellers are unaware that brass from government liquidations for scrap can be put through a machine that will make the brass unusable. Even SAW brass can be weakened if sustained full auto got the gun hot enough to cook of a few rounds from what I read on the interweb. Its on the internet so it has to be true.

Your referring to a popper or popper furnace. The liquidation companies are required to notify you the brass has been through the popper. This brass however has been in my possession since before poppers were used. I really believe it is bad brass. (it has an unknown past, Friend had another friend load it for him. I pulled the bullets, powder, primers and converted it. or it could be an annealing gone bad) Guess I wont do that again. Convert only brass you shot once from the box.

[WILCO]

None of the above!

Checked the head spacing in multiple ways before ever firing to begin with. Then after this happened Checked with go/no-go (and checked the other 2 uppers the shop had, all good)

No issues with the process, dont recall saying that.

The only thing you could call a substitution would be the primer, I dont use Winchester primers, only CCI. I have read over 100 pages of others experiences I am not the only one using CCI #41. The bullet and powder are in hornady #9, My initial statement about the primer was a question not a statement. (most of others experiences were than below 18 the gun didnt cycle properly.

Not near max charge. 19gr is right in the middle. 22gr is the listed max load. The manual has only a 6gr spread

Been reloading for 10 years and am very meticulous about everything involved. Reading all the info and asking questions makes much more sense than assuming allot and making negative comments. Have reloaded 10s of thousands of rounds with never and issue until this. Comments like this make people want to not ask questions which is not what this forum is about.

Everything I mentioned is based off of what you've reported. Go back and re-read your posts. I didn't make any negative comments, just stated facts. You've experienced a major "WTH" situation and it doesn't matter how many rounds you've loaded, you stepped in a big old pile of something and aren't being proactive about it. There's a difference from go back to square one and be safe, than going in circles with 50 different answers. Like I said earlier, case failure is a basic condition of reloading. When it occurs, it's time to step on the brakes and look back. You are doing something wrong.

Best wishes as you move forward.

[Phoenix]

Shot the new brass today. 19gr was the best of the lot. Everything went fine. The factory brass (my loads) even chrono'd within 20fps of the converted brass. Didnt change anything but the brass. Converted 20 more and loaded .2 increments to see if it can be fine tuned. I doubt it is going to get much better than .6" three shot group though. The factory loads did a .6" three shot group the last time. The reloads did 2" three shot group. (might have been me though)

No complaints here. Cant help but wonder what they did to that brass to make it that soft to blow out a load that doesnt even flatten primers.

I suspected the brass from the beggining but in 10 years I never had a reload of mine have a case failure. I just wanted to see what others thought. Thanks for the responses.

[John 242]

Shot the new brass today. 19gr was the best of the lot. Everything went fine. The factory brass (my loads) even chrono'd within 20fps of the converted brass. Didnt change anything but the brass. Converted 20 more and loaded .2 increments to see if it can be fine tuned. I doubt it is going to get much better than .6" three shot group though. The factory loads did a .6" three shot group the last time. The reloads did 2" three shot group. (might have been me though)

No complaints here. Cant help but wonder what they did to that brass to make it that soft to blow out a load that doesnt even flatten primers.

I suspected the brass from the beggining but in 10 years I never had a reload of mine have a case failure. I just wanted to see what others thought. Thanks for the responses.

Glad that the new brass is working out for you.
You mentioned that the problem could have been an "annealing [job] gone bad." That would make sense. I've been warned not to heat the case head when annealing, because it will soften. Well, it appears that you have soft case heads, for one reason or another.

I wonder if this problem brass left the factory this way, or if the previous owner had something to do with it?
Tomme boy mentioned earlier that LC brass is soft. I wouldn't have figured that it would be THAT soft!

Anyway, I'm glad that you were willing to share your 'problem' with the group and glad that everything is working fine, now. I learned a little bit, and I appreciate it.
Take care.

[freebullet]

Glad you didn't have any additional issues. I've had brass that my gut said "throw it out" & I do just to be safe. When the history is unknown extra caution is your best practice. I sure wouldn't complain bout the groups yer latest batch made.

[WILCO]

Shot the new brass today. Everything went fine. The factory brass (my loads) even chrono'd within 20fps of the converted brass. Didnt change anything but the brass. Converted 20 more and loaded.

I think it's a little more involved than that, as there are too many variables at play here to just change one shoe and keep running. But hey, you think you got your answer, so best wishes as you go forward.

[xacex]

Your referring to a popper or popper furnace..

Yup. Some of that will make it out in to the public if not by the purchaser, by someone picking it out of scrap at the recycle yard.

[Phoenix]

I think it's a little more involved than that, as there are too many variables at play here to just change one shoe and keep running. But hey, you think you got your answer, so best wishes as you go forward.

The only course of action would be to proceed with caution (which is what I have and will be doing) Never said the problem is totally solved. (it may be but assumption is bad news as well)

There is an old troubleshooting axiom. "you can't fix what isn't broke" you cannot take additional steps until you have a new symptom. You change one variable and the problem goes away you can only proceed with caution and move forward. That is why I use kevlar shooting gloves and a pair of beretta shooting glasses when I shoot new loads. (I will continue to use caution until I have at least a few hundred rounds through the gun)

Lets look at the situation.

Headspace checked - passed
chamber and bore checked - nothing visable.
chamber dimensions checked - same as other two uppers of the same make (at gun shop)
Bolt checked - passed, no gas cutting, no cracks, nothing to see. (the bolt has 25 rounds on it, pretty easy to see an issue when it is almost brand new)
Brass changed, all other variables stayed the same. This is proper troubleshooting technique, change one variable at a time otherwise you will never know which variable was the cause and you could have an issue later that you are not expecting if you change one of the additional variables back or to something else.
loads chonographed - within 20fps of the factory rounds (factory rounds have little to no primer flattening, same as my loads)
Tight groups - The reloads and the factory rounds have the same size three shot groups.
no pressure signs - primers rounded (same as the factory rounds) brass didnt stretch at all they were all 1.358 the 10 fired cases are still 1.358
no backed out primers, no cratering
manufactured upper, not my build

The brass was the only unknown in the equation, I changed it because unknowns are the first thing to be changed in a troubleshooting situation. Yes it is possible the primers, or powder could be somehow bad but those cannot be eliminated unless the unknowns are removed. I have a different lot of AA1680, and a different lot of CCI#41, but again changing multiple variables isnt good either. Once the brass was changed all other expectations fell into line.

What exactly would you like to change when the symptom has gone away and no other symptoms are present?

[Love Life]

Check the NevadaShooters forum. There is a man on there with very similar blowout on a 5.56 rd. It destroyed his bushmaster.

A bunch of similarities between your blow outs and his...

[Phoenix]

Yup. Some of that will make it out in to the public if not by the purchaser, by someone picking it out of scrap at the recycle yard.

I have read (since this happened) of others thinking annealing is done by putting the brass in the oven at 450 degrees for one hour. All I can say is they have issues in their future.

[Phoenix]

Check the NevadaShooters forum. There is a man on there with very similar blowout on a 5.56 rd. It destroyed his bushmaster.

A bunch of similarities between your blow outs and his...

Except one important one. These were not very high pressure. The primers are still rounded. He obviously had some serious pressure from that round, I would say 100k+ psi The atomized brass (brass plated bolt) and gas cutting the bolt in half really are the key. Not sure that would be possible without loading the wrong powder. Wow something was seriously wrong there. wrong bullet, wrong powder, obstructed barrel at the throat.