Shooting some Federal XM193 (120rds)this weekend and noticed that my fired cases were showing ejector swipes and had about 7 raised primers. Rifle is a 14.5 BCM, H2 buffer with standard spring. Has 4,000 rds through it with the last 2k being Wolf gold. My question is will a heavier buffer (H3, H6) help mitigate the pressure issue?
No,the ammo is just hot. The heavier buffer will only slow down the cycle rate of the weapon,and delay the unlock slightly. Xm193 is a full power load,it doesnt get much hotter than that. It almost looks like there was some pressure leaking around the primer pockets also.
Can you post some pics. of the sides of the cases something looks funny,anyone else see pitting on the sides of some of the cases??? Is there a ring around the fireing pin hole were gasses were escaping around the primer pockets?
I do believe the X in xm meens there military rejected m193 brass. I could be wrong about this though. Hopefully the experts here will chime in. Just my 2 cents.
With 4000+ i would change the spring in it. If you search you will find out how to measure it to see if its time to change it,but i would just do it a bufferspring isnt expensive at all. The shipping will probably be more…lol
Thanks for the reply Texasgunhand. The case on the left is what the fired cases with the raised primer look like. You can see where the gas was leaking around the primer. The crimp held the primer in. No pitting on the cases, just dirty. I was planning on changing the spring out anyway, if a heavier buffer would help lessen the wear, I was going to grab one also. I have 2.5k of the XM193.
Keep an eye on the bolt face around the firing pin hole, leaking primers can couse pitting. It would be best to post your question in the m4 general or technical on which buffer to buy,theres alot of guys running 14.5 barrels there. Bcm is a favorite around here,so you should get proper help.
I wouldn’t continue to shoot that stuff. The bright, shiny swipes are too much for my comfort level. A heavier buffer will only slow the bolt speed down a little, but won’t make firing that ammo any safer.
Markm, thank you for your response. That was what I thought. I have read before where you pulled bullets and dropped the powder charge, was it worth the effort? I bought this ammo back in 2012 so if I tried to sell in I would lose. Any recommendations on a bullet puller that you would use about 2,500 times?
Bullet pulling is somewhat painful. I got about 1000 damaged Independence M193 rounds from Iraqgunz a year or so ago and pullet them all down. You have to love your time in the loading room a lot to do this… and break it up into many sessions. 
You can surely get your money out of it. There are likely guys out there who blast away and don’t check their brass so thoroughly. I, however, have a dedicated press on my bench for pulling .223/5.56 bullets. I have one of the collet dies where you twist the top with a handle, but I’ve read that the Hornady model with the vertical lever works better.
smithje
Your shooting factory ammunition and not reloads which makes me think something else is wrong to cause the excess pressure. So when was the last time you attacked the chamber with a AR15 chamber mop and brush?
Now clean the crap out of your chamber and bore and pay attention to carbon buildup. A buildup of carbon in the chamber neck area and throat will cause a increase in chamber pressure.
To make it easy give the bore a shot of the carbon cleaners listed below and then use a foam bore cleaner and let it sit overnight and then repeat.
Bore Cleaning Methods and Materials
How to Clean Your Barrels with Less Effort and Better Results
http://www.accurateshooter.com/technical-articles/bore-cleaning-methods-and-materials/
Then go out and shoot a few rounds of the M193 and test for pressure signs.
bigedp51
After reading your response and rereading texasgunhand’s previous reply about thecases looking dirty, I think (hope) that a dirty chamber is the issue. I gave it a solid scrubbing and will try it again this weekend.
Altho,keeping the chamber clean and carbon free is important in these and all rifles.
I think the ammo is just WAY to hot,xm193 is known to be hot,but if its trying to push the primers outa a crimp thats just way to much pressure. They should stay in place without the crimp. The military wantng faster and faster ammo they have reached the MAX for the .223 cartridge…
Ive seen guns with so much carbon in the chamber it was imprinting on the shoulders of the cases,but it wasnt pushing the primers out of the case and they were not even crimped. If markm says he would not shoot anymore of it, i dang sure wouldnt.
You may wana call the manufacturer and see if they will take the ammo back on trade alot of the time they will,dont think they dont make mistakes they have recalls all the time even on .22 ammo. I wouldnt chance shooting anymore with out contacting them, unfortunately this is how they find out about problems is through customer contact. Dont blow up your gun becouse of something like that.
Be sure and have the lot number of the ammo when you call. Should be on the box. It doesnt cost anything to call,if you feel their giving you the run around ask to speak to a manager and hold your ground till you get a answer YOUR comfortable with. If theres a bad lot out there your doing yourself and them a huge favor.
texasgunhand
I do not see any crimped primers being pushed out of the primer pockets.
And I also do not see Federal intentionally selling any type M193 ammunition that exceeds max allowable pressure.
I shoot large quantities of XM193 and M193 ammo and have NEVER seen a over pressure issue with case head swipes and the brass flowing into the ejector.
And the ammo the military is shooting now is M885 and NOT M193 which is sold for commercial use and to law enforcement agencies.
Below are three five gallon buckets of once fired M193 brass and not one of the cases has case head swipes or brass flow into the ejector.
There is a difference between $hithouse rumors and first hand knowledge and you are the one asking 90% of the questions in this forum.
Lake City brass has the hardest brass in the base of the case compared to commercially made .223 brass and it would take over 70,000 psi to get the brass to flow into the ejector.
I will stay with my guess of carbon buildup in the chamber and throat and add the possibility of oil/grease in the chamber and in the bore.
smithje
I hope you are not running your AR15 too “wet” and allowing the oil to enter the chamber and bore.
It may not be intentional, but there’s a lot of blode up guns in the wake of XM193 and Independence M193 too.
This so called problem has been going on for a long time and the link below is dated June 2005 and has been linked to chamber size and carbon buildup.
Overpressure Problems / Blown Primers * UPDATED * MORE TEST RESULTS *
http://www.ar15.com/mobile/topic.html?b=3&f=66&t=235071&page=1
I have a “factory” off the shelf Savage .223 with a longer throat than either of my AR15 rifles do and this .223 shows LOWER pressure signs using M193 than my AR15 rifles do.
We need to know more about the rifle, its chamber and how often and how well it is cleaned before doing any more guessing.
Something taught to me as a aircraft inspector.
“97% of all errors are human errors and only 3% are actual mechanical failures”
Meaning 97% of all aircraft crashes are due to human error and only 3% were due to actual mechanical failures.
The OP said he had 7 raised primers,xm193 is crimped you can see the crimp in the pics the OP posted.
Xm193 and independent both have to be watched carefully. I wont even shoot independent ammo at all becouse of the over pressure. I also shoot very little XM193 becouse i dont see a need to put that much wear on my guns to shoot at paper.
There have been so many threads on both here i cant believe people even buy Independent ammo at all. If you look at the m4 gen. and tech. forum you will see several post on both, some with pics of some nice guns tore up from them.
Ive seen factory ammo malfunction MANY MANY times from squibs to blown up guns so bad it cracked the stocks,iam talking about nice hunting rifles and pistols not just m4s.
No offense big you may know a lot about reloading but you cant tell me what ive witnessed with my own eyes over 40 years of shooting. One of my shooting buddies just shared a story of Winchester ammo 3 deep in a box blowing up a rifle in his hands many years ago. Or me watching a guy get 2 squibs in the middle of a new box of PMC 9mm, not knowing what happened ,he was fixing to pull the trigger with 2 bullets in the barrel before i stopped him. Brand new berreta and a brand new box of pmc he got when he bought the gun.
I was freinds with the owner of the gun store he bought the pistol at who beat both bullets outa the barrel when he took it back. Type in ammo recall at yahoo and just look at what they admit has a problem from.22 to 500 s&w. This is why i have ammo reserves not to stockpile but to see if there will be a recall. I shoot a old box and replace it with a new one checking the recall pages frequently just in case. Some of my rifles cant be replaced becouse of the age or the fact they dont make them any more such as my rem. 600 mohawk in 6mm my favorite deer rifle. I wouldnt trade it for a brand new 700, it was my grandfathers and cant be replaced.
Sure if you dont do the proper maintenance on a gun there will be problems. The rifle he blew up was cleaned regularly and the pistol i spoke of was never fired brand new outa the box,first time firing and the guy was half way through the box when he got back to back squibs,maybe the next round was hot maybe not but if i wouldnt have been there he would probably be missing an eye or finger right now. Becouse of that i have never fired one round of pmc ammo in my life. Many many have but i never will.
I just had an old lot of fed. .22 that only half would fire, it wasnt the gun , its never had a problem in 60 years before or the 600 rounds since then. Just with 6 boxes all the same lot number. I must be doing something right ive got guns that were bought new in the 1930s that still shoot great and my grandfather wasnt a cleaner his idea of cleaning was spraying them with oil and putting them back in the cabinet. It wasnt till i came around they got cleaned properly,i bet that old mohawk doesnt have 4 boxes of shells through it even today,but its put a lot of meat in the deep freezer over the years.
Below are my photos of my hand holding two types of XM193 ammo that I have fired countless rounds through my two AR15 rifles and I have NEVER had a single problem with this ammo. If YOU and others can’t grasp the fact that the vast majority of firearms mishaps are caused by the person pulling the trigger. Then you need to get a grip on the rumors you are posting in forums and face the fact of human stupidity that happens with firearms. Yes shit happens and bad ammo can slip through the cracks, BUT I will say this again “YOU” are the one asking the most questions in this forum and this shows your inexperience in reloading. This can be cured by “YOU” reading a lot more reloading manuals and reloading information.
There is carbon all over the OP cases, he had a dirty chamber that he said he cleaned and I’m waiting for his reply if cleaning his rifle fixed the problem.
This is very simple, NONE of us are holding the OP rifle in our hands, and we do not know how often he cleaned the rifle. We do not know the type AR15, what type chamber he has, and we are all just guessing at the problem.
And I do not care what you have seen because your are a faceless screen name at a reloading forum. And the biggest problem forums have are midgets sitting at their computers pretending to be giants.
I’m sorry for being such a hard ass but I spent the last half of my working career as a inspector watching other people making stupid mistakes. And the vast majority of them made these mistakes because they thought they were so smart they didn’t need to read the manuals freely available to them.
Yes shit happens and the vast majority of it is stupidity and arrogance of the people it happens to.
You still cant tell me what ive seen with my own 2 eyes any more than you can see the OPS rifle in the pics.
as far as post go iam new, but theres post ive seen on here on your arrogance. Ive seen the same pics and posts you have here on ar15.com etc. Ive got news for you this is a gun board its here to chat and ask questions,dont like mine feel free not to answer.
You are the typical internet bully that thinks you are the only smart guy in the room. I dont give a damn about what some internet tough guy thinks about me,maybe thats something you havent read in a book. Thees so many more people on here that have actually helped me. Unlike you who seems to sit in his basement and talk smack. You suck the life outa this room ,maybe its time you put that book down and go out and enjoy yours some, tough guy. The OP states its a bcm upper,read the post.THEN. FO…ill take markms opinion over yours anyday of the week.
texasgunhand
Don’t blame me for your lack of knowledge and experience and if you can’t take criticism you need to find a new hobby. You didn’t fix or solve the OP problem and all you did was write about what you have heard and NOT through experience on the problem. Now get a grip, all you have been doing in this forum has been asking questions and now you think your handing out expert advice. Why don’t you spend more time reading your reloading manuals and less time asking questions. I say this because the facts are in the books and manuals and forums are full of people like you guessing at the actual problems.
So stop your whining and crying and lets find out from the OP what the real problem is.
We will find out,iam not crying trust me you dont know me. I dont care about your opinion any more than you care about mine. So you stop your tired old crap,iam not the only one who feels the same way. Your opinion is only that , your the one attacking me not the other way around,this is were your going wrong. And your still not the smartest guy in the room. But i am smart enough to know you cant teach an old dog new tricks…rofl
I refer you back to the FO in my previous post. You should get a book on manners, then read it.,maybe talk to someone about your bullying issues while your at it.
Were did i say i was an expert,i gave my opinion to the OPS question. I guess we all cant be experts on everything like you. You should feel so good about yourself.
Iam sure you do, and thats some expert advice right there…
Theres absolutely nothing wrong with the advice i gave the OP. None of it will cost a dime to do,nor is any of it a lie. You just have issues,either with me or in once again with the problem of thinking only your opinion matters to the rest of the world. I know you will find it hard to believe,it doesnt.
God help us if your wrong i guess the sun will no longer shine nor the birds tweet,it will be a truly sad world to live in. I can only imagine that its like you feel everyday living in a world with other people in it.
Whaaa!!! the big bad man hurt my feelings
And my favorite post.
Now get a grip, stop crying and read more and post less, who do you think your fooling.