Bushmaster XM15 stuck cartridges


PDA






xsquidgator
January 21, 2008, 08:50 AM
I have a slightly different issue than the usual "AR15 stuck case" thread, and I have done some searching w/o seeing this issue.

I have a Bushmaster XM-15 (556 chamber) that I bought lightly used a month or two ago. It's had a total of maybe 500 rounds fired through it, of which I've fired maybe 300 or so. The problem I have intermittently is this:

Once in a while when I'm shooting, for some reason I'll stop shooting before the magazine is emptied. No problem, eject magazine, use charging handle to pull bolt to rear and eject unfired cartridge, right? Most of the time this works ok. But now twice on two different days I've had an unfired cartridge get good and stuck in the chamber, the charging handle just WOULD NOT pull back, perhaps a fraction of an inch if I really gronked on it using my hands. I could tell it moved a little because the forward assist would then move forward a little bit.

I tried working it back and forth with the charging handle and the forward assist, to no avail. Since I was at the range, I solved the problem both times it's happened by firing the round. Each time I did this, the ejector removed the round like there was no problem, chamber was totally empty and no damage to the case rim that I could see. It was just so tight I couldn't budge it by hand. So far the most I've shot in a single range session is 100 rounds or so, usually less, and I clean the rifle after every session even though it's probably not necessary. The first stuck cartridge experience happened a few weeks ago, so I bought a 223 chamber brush and used it the last time I cleaned the rifle. Yesterday I had another stuck case.

This rifle has never had steel case ammo in it as long as I've had it, and I doubt it's ever had it. (It came with 300 rounds of S&B brass cased ammo that the previous owner hadn't used). I've fired 100 rounds of this, and maybe 200 rounds total of reloads I've made from range pickup brass. Now that I think of it, I don't recall exactly what kind of brass it was that got stuck, or if it was the same kind both times. After my first couple of experiments loading range pickup brass to make sure I could do it ok with 223, I segregated what I had by headstamp and for now I'm using either "R-P 223" or "S&B 223" brass.

My resizing die is a standard Lee decapping/sizing die in a Lee 3-die set. I don't recall having any issues when resizing these, but a case not properly resized is the only thing I can think of. I'm concerned about this because I don't want to sometime in the future chamber a round and not be able to get it out (I may not be at a range where I can just shoot it, and there's something not right if that's the only answer).

My questions for the board are:
1) what do you think the problem is (resizing problem?) and what would you do about it?
2) if you experienced a stuck unfired cartridge like this, how would you get it out? The bolt and bolt carrier are stuck forward when this happens, and so I don't feel comfortable getting a rod and pushing it out the breech like I would for a stuck fired case.

This rifle is a nice one I think, I can shoot 1.5 MOA with it with mediocre skills and I'm looking forward to improving with it. But, this is causing me some concern. I also reload several pistol calibers as well as 7.62x39, 7.62x54R, and 8mm Mauser, all using the same kind of Lee die sets, and have never had this problem with any of those loads.

If you enjoyed reading about "Bushmaster XM15 stuck cartridges" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!
hqmhqm
January 21, 2008, 09:37 AM
When I had fired shells get stuck in my 870 Remington, someone recommended polishing the chamber with some fine steel wool. That seemed to help in that case, I don't know if it might help in your case.

I guess the question to ask is, does this only ever happen with your reloads, or does it happen with factory ammunition?

xsquidgator
January 21, 2008, 09:49 AM
I guess the question to ask is, does this only ever happen with your reloads, or does it happen with factory ammunition?

Yes, I forgot to clarify: it has only happened with my reloads. The first day I had the rifle I shot about 100 factory S&B rounds through it, and after that my dies and components arrived so I've shot only reloads since then.

This problem is only occasionally; I tried to reproduce it yesterday using a mix of different headstamped brass reloads and couldn't get it to get stuck again.

I'll think about the steel wool thing, but won't do it for a while if I do do it. My chamber is chrome-lined and I'd hate to mess it up. I'll use a chamber brush again. And this time, I'm going to collect the brass that gets stuck and extracted to see if there's a common thing. Thinking about it, I'd expect to see the stuck cases be larger in diameter.


There is one other possible explanation, a stretch but possible, now that I think about it yet again. I may have done some of my case preparation steps out of order. For some of my case prep, I deprimed, resized, and then trimmed the cases using a Lee case length gauge and case trimmer. I later discovered that when done in this order (rather than trimming, THEN resizing as per my reloading guide) the neck of the case gauge opened up the case neck a little bit, sometimes causing problems with "loose" bullets when I later seated the bullets. The Lee case length gauge and trimmer is a bit "snug" when it goes into a resized 223 case. I'd forgotten this little detail until just now.

I wonder if it's possible some of these rounds that I made like this have slightly oversized necks and that's where the cases are sticking? Could the order of case preparation steps have made this much of a difference?

taliv
January 21, 2008, 09:53 AM
use a case gauge.

Bartholomew Roberts
January 21, 2008, 11:18 AM
Sounds like a reloading issue given your description and I am not qualified to comment on that.

2) if you experienced a stuck unfired cartridge like this, how would you get it out? The bolt and bolt carrier are stuck forward when this happens, and so I don't feel comfortable getting a rod and pushing it out the breech like I would for a stuck fired case.

Keeping the muzzle pointed in a safe direction, slam the butt of the rifle on the deck as you simultaneously pull on the charging handle. This will clear most stuck cases of the type you are describing.

Chris Rhines
January 21, 2008, 12:10 PM
It sounds to me like you need to bump the shoulder on your brass back a little farther, and/or trim your cases a little shorter.

- Chris

xsquidgator
January 21, 2008, 12:12 PM
Keeping the muzzle pointed in a safe direction, slam the butt of the rifle on the deck as you simultaneously pull on the charging handle. This will clear most stuck cases of the type you are describing.

Cool beans, that doesn't sound too unreasonable. I take it that "it would be bad" if I were to beat on the charging handle while applying the latch?

strat81
January 21, 2008, 12:49 PM
the neck of the case gauge opened up the case neck a little bit
!
Ima have to look into that. Some of my M43 loads haven't had good neck tension, but it was intermittent.

JonB
January 21, 2008, 01:05 PM
There was a thread recently in the Reloading forum on the order to deprime, size, trim. Both of my manuals have the same steps (deprime/resize then trim) but apparently there is another manual that has a different order.

Link to Thread here. (http://thehighroad.org/showthread.php?t=329513)

HJ857
January 21, 2008, 02:41 PM
Are you using the Lee factory crimp as your final step? If you're getting a flared case neck, the crimp die ought to take care of it. If that's not the problem, I'd guess the sizer die needs to be screwed down a quarter or half turn.

rcmodel
January 21, 2008, 02:53 PM
It sounds like a collapsed case shoulder during the bullet seating or crimping operation.

This can be so slight you can't even see it, but it will stick a round in an AR so tight it won't fully lock, and it won't come back out either!

Even if you are not crimping, then make sure you lightly lube the inside of the case-necks before sizing.
Sometimes, the dry expander button can chatter & drag hard enough to pull the shoulder back forward with it.

If you are not chamfering the inside of the case-necks, do so.
Sometimes a bullet base will put up a fight going in an un-chamfered case and collapse the shoulder slightly.

If you are crimping, get a Lee .223 FCD crimp die.
Unlike the seating/crimping die, there is positively no way you can buckle a case shoulder with it, because all the crimping pressure is supplied by the shell holder, not the case itself.

You might get an L. E. Wilson or Dillon .223 case guage and drop-check every finished round. You can be sure they will all work then.

I'm betting one of these things is your problem!

http://i81.photobucket.com/albums/j219/rcmodel/KTOG/1224.gif
rcmodel

xsquidgator
January 21, 2008, 03:33 PM
RCmodel,
Hmm, I'll re-visit this, sounds like a potential cause for my problem.
I do crimp using the Lee FCD, and I chamfer the outside and the inside of my case necks. I did have some issues with not lubing the inside of the case necks (got several cases stuck in my sizer die with the rims torn off when the expander bell got stuck), I hope I have fixed them.

I'm also going to re-read my loading guide, I could swear my Lee guide said to trim, then resize the cases. I had been trimming last since I figured the resizing operation would possibly lengthen at least some of the cases.

Gotta think this over. But I'm glad to hear this kind of thing probably isn't a TOTAL mystery like it was to me when it happened.

Float Pilot
January 21, 2008, 04:18 PM
Remember your rifle was made to fire military spec 5.56mm ammo and not really commerical .223 Remington. Mil spec 5.56mm in sized a tiny bit smaller. They do that for reliabilty, particularly in a hot, dirty rifle.
I'll bet the rifle is still fairly warm when this problem occurs. It sounds like you have already been given the proper advise regarding your handloads.

rcmodel
January 21, 2008, 06:12 PM
It has nothing to do with 5.56 vis .223 chamber or case dimensions.

You use the exact same .223 sizing die & headspace for both of them when you reload them.

Partial case shoulder collapse for some reason is about the only logical reason this can be happening.

I have shot a Colt SP-1 without a forward assist since 1970 or there abouts.

I can assure you, both .223 & 5.56 sized in a standard .223 reloading die will both work slicker then owl dodo in a 5.56 chambered gun.

Until you get one stuck with a tiny, invisible, partially collapsed shoulder!

I'm also going to re-read my loading guide, I could swear my Lee guide said to trim, then resize the cases.I don't know what it says, but you always have to trim after sizing.

Normal case trimmer pilots are made to perfectly fit a sized case neck. They are loose and wobble on unsized case necks.

The cases get shorter when you fire them, and grow longer when you resize them.

http://i81.photobucket.com/albums/j219/rcmodel/KTOG/1224.gif
rcmodel

jonboynumba1
January 21, 2008, 06:35 PM
Like other have said check your die and make sure it's really bottoming out on shell holder (if lee or similar dies used) I'resize and deprime...then I usually tumble/clean...I do it once in treated polishing compound media and once in dry mostly clean media to final polish and get any remaining junk off...then I do case prep (sort and cull...clean primer pockets (ream primer crimps if called for)...uniform flash holes, trim cases and campher inside and out lightly. Then prime (Use the lee hand priming setup...only thing I ever use...it's cheap but it works great and has total feel/feedback) charge seat and crimp with a Lee factory crimp die. When in doub get out the lee book and some mics and check you case dimensions with the diagram in the book. The usually list max sammi specs and use close to max demensions in their dies. Could be you need a light polishing in your chamber but that would be the LAST thing I'd try. If it shoots M855 and WWB/Rem/Fed ball ammo fine you know it's your reloads. If it gets picky with M855 or ss109 you might have a tight chamber. If all else fails get another set of dies and try them...I've had good luck with lee dies. I've seen some odd variances in some of the "better brands" in a few calibers. First thing is make sure all the slop is out of your stroke and tighten down the FLS die a 1/4-1/2 turn.

If you're l crimping with the seating die then my money is on that...get the lee FCD for $10 and follow the directions for setup. You can use a little less or a little more crimp than what it shows but don't get too crazy screwing it in a lot farther. It's a gotta have it though...I never taper crimp anything anymore...too easy to have issues if you aren't paying attention or have some weeker brass...I never get as good an accuracy out of the old sty;e crimp as I have with the lee FCD. Sometimes changing that one factor alone has made huge accuracy gains reguardless of seating. (even start presure...I'm a believer)

4v50 Gary
January 21, 2008, 06:42 PM
Take calipers to your reloaded ammo. Check with the SAAMI chart to see if they're within spec.

SlamFire1
January 21, 2008, 08:12 PM
I would say that your brass is oversized for the chamber. The fact that some of them work and that others do not is an indication that your sizing die is not sizing all of the cases enough.

So, you feed in this oversized case into your chamber, your bolt carrier has enough energy to swage the thing into the chamber, and all you can do is shoot the thing out. In some instances I have seen oversized cases stay in the chamber. The rim goes, but the case stays.

Brass has springback. You can size a huge balloon cases, but the sucker will expand a bit back. Your standard sizing die is squeezing some down enough, but not all of them. You ought to see what commercial reloaders use to size brass. They have these parallel plates that totally swage cartridges, they can roll a telephone pole down to a pencil. Your equipment is much more limited.

The solution: Get a small based die and set the sizing die up with a cartridge headspace gage. Size to gage minimum.

Do not ruin your chamber in anyway by polishing the thing. EEK!

lamazza
January 21, 2008, 09:05 PM
I was getting this problem when I used a Lee progressive press to resize.
I think that the progressive was not robust enough for resizing rifle cases.

Also, Lake city brass seems to expand a bit more than other brass-in my experience.

rcmodel
January 22, 2008, 02:05 PM
Before you get all excited and buy a small-base die you don't need:

Smoke a case with a candle flame and figure out exactly where it is tight & sticking in the chamber.

Dollars to donuts is a partial shoulder collapse you can't see without a case guage to find it first!

http://i81.photobucket.com/albums/j219/rcmodel/KTOG/1224.gif
rcmodel

another okie
January 22, 2008, 05:07 PM
I agree that you should get a case gage.

xsquidgator
January 22, 2008, 09:32 PM
Thanks for sharing your opinions, I have some things to think about now and to try out. I guess I'll have to re-read the instructions on my Lee dies also... just to be sure I have the sizing die adjusted properly.

I agree that you should get a case gage.

Is this (http://www.midwayusa.com/eproductpage.exe/showproduct?saleitemid=268983&t=11082005) kind of case gauge you mean?

rcmodel
January 23, 2008, 06:16 PM
I have an L.E. Wilson guage, but I think that one should do the same thing.

http://www.midwayusa.com/eproductpage.exe/showproduct?saleitemid=456614&t=11082005

http://i81.photobucket.com/albums/j219/rcmodel/KTOG/1224.gif
rcmodel

Walkalong
January 23, 2008, 06:45 PM
I'd go with the L.E. Wilson over the Lyman, if it was me.

another okie
January 23, 2008, 08:14 PM
I could be mistaken, but I think the Lyman is just a case gage. The L.E. Wilson is also a cartridge gage, allowing you to check a finished cartridge. That's what I have, anyway, for .223 and it has caught a few oversize shoulders for me.

http://www.midwayusa.com/eproductpage.exe/showproduct?saleitemid=456614&t=11082005

xsquidgator
January 23, 2008, 09:39 PM
Another question about this issue - is my problem with the shoulder that the case/shoulder is too long? Or is it that the diameter of the case at the shoulder is too big? Or is it possibly that the sizer die isn't reaching all the way down to the base of the case, so that the part of the case right above the rim is oversize in diameter?

And, does a cartridge gauge provide some sort of length AND outside diameter check?

SlamFire1
January 23, 2008, 10:16 PM
And, does a cartridge gauge provide some sort of length AND outside diameter check

Without gages, all your questions could be yes, no and maybe.

However the last one, quoted above, a typical cartridge headspace gage measures length only. The Wilson gages are cut "fat" between the shoulder and the base.

I wanted a gage that was exactly the same as my CLE chamber. So I paid Frank White of Compass Lake to cut me a cartridge gage with the same reamer that cut my chamber. Now I have something that will measure length and width. Cost about $40.00.

xsquidgator
January 27, 2008, 09:44 AM
Looks like I waited just a little too long to revisit this and my original thread disappeared, so please bear with me.

The gist of my problem is that when reloading .223 rounds for my 5.56x45, 1/9, 16" HBAR Bushmaster carbine, some cartridges seem to get stuck in the chamber before firing. I discovered this by accident when for some reason I stopped shooting a string before the mag was empty, and the bolt was stuck TIGHT when I tried to work the charging handle to eject the unfired case.

I posted this a week or two ago and got several thoughtful suggestions. The main suspect as I recall was possibly that I could be somehow partially collapsing the case shoulder during resizing or seating/crimping, which could make the outer diameter of the case be a little larger than it should be. A second possibility was that maybe I wasn't going all the way down to the cartridge base when resizing, and that maybe the base of the cartridge was oversize as a result.

I will hopefully get a chance today to test the second idea out, as I made another batch of rounds and made darned sure to go ALL THE WAY DOWN when resizing these. I have another batch of reloads I'd made where I didn't pay special attention to this detail, so I'm going to try both and see if I can duplicate the problem. (Both lots of reloads are using the same "R-P 223" brass)

My question today is, if the first problem, an oversized shoulder, is the case, what would you do to try to fix it? I use all Lee dies, and as I do with all my rifle reloads, I use 3 Lee dies (sizing/decapping, seating, and factory crimp die). I don't think my bullet seating operation is the culprit, as all it does is to seat the bullet. I like to put a decent crimp on my cases with the FCD, is there any possibility that the FCD is putting too much downward force on the case shoulder?

I measured the shoulders of some of my cases with calipers and compared them to some Remington 223 store-bought ammo I have. The shoulders on the commercial ammo seem to me to be about 0.350" whereas mine are about 0.352". It's hard to tell for sure because the measurement is made on the part of the case where it starts to taper off. The other thing that's kind of odd is, what IS the shoulder size supposed to be? I found the diagram below online, but it's a little different from the one in my Lee #2 guide. Lee says the shoulder should be 0.350" but this one below says 0.354".

http://accurateshooter.net/Diagrams/223remx330.gif

Anyway, forgive the rambling, long story short is that I suspect that I may have a shoulder issue on my 223 reloads, perhaps somehow related to partially collapsing the shoulder at some point. Any suggestions on what I should do differently? I reload 3 other rifle calibers, do things the exact same way I do with these, and have never had this kind of problem. I'm curious as to what the peanut gallery might have to offer for advice.

xsquidgator
January 28, 2008, 03:24 PM
Ok, it's a dull subject. Just in the interests of completeness though, I think I've shed some light on the problem after a range-test session yesterday.
1) Ran 100 rounds of reloads using 223 brass (R-P if it matters), could not reproduce the stuck cartridge problem although I tried every combination I could think of, from cold chamber to rapid fire and then try to eject chambered round from a hot chamber. No problems whatsoever.
2) Then I ran maybe 5 rounds of misc brass reloads through the rifle, and got the stuck cartridge when chambering a Lake City headstamped reloaded 556 brass round.
3) Even when stuck, the technique of safe-ing the rifle and bumping the buttstock on something solid while pulling the charging handle, worked perfectly. Thanks for the tip!

So, I think I'll be careful about using 556 brass until I figure out more. But I have hundreds of range-pickup 223 I can use before I need to start using my range pickup 556 brass.

HJ857
January 28, 2008, 04:02 PM
You may also want to check the case length. The Lee case length gauge/zip trim combo is pretty efficient and guarantees a good length.

Anyway, just a thought. I recently had similar problems with a different AR caliber and it turned out to be overly long case length.

xsquidgator
January 28, 2008, 04:33 PM
You may also want to check the case length. The Lee case length gauge/zip trim combo is pretty efficient and guarantees a good length.

Anyway, just a thought. I recently had similar problems with a different AR caliber and it turned out to be overly long case length.

I'm pretty sure I'm good there - I use and like the Lee Zip trim and case length gauge/cutter. My trimmed cases are within 0.010" of what the Lee manual says they should be. I suspect a case diameter issue with the LC brass, perhaps it expands slightly after being sized unlike my 223 brass. Even if I don't end up fixing the root cause I'll be happy now 'cuz I know how to extract one of these stuck rounds if it happens again (buttstock tap while pulling charging handle).

HJ857
January 28, 2008, 05:24 PM
It certainly is an interesting problem. I've been using a good bit of LC and IMI range brass with Lee dies and have not had any issues. In fact, I have not been sorting brass at all, I have FC, R-P and Winchester and probably others mixed in there as well.

Just from a knowledge base aspect, I'm hoping for a definitive answer to your problem.

If you enjoyed reading about "Bushmaster XM15 stuck cartridges" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!