BM XM15E2S - FTE's

[Werewolf]

Arghghgghg!

A brand new Bushmaster XM15E2S and after 80 rounds had 18 failure to ejects. By that I mean it wouldn't spit the brass out the ejection port.

What' happening is that the brass is getting hung up on the bolt face. As the bolt goes forward the brass doesn't get spit out the ejection port and the next round in the magazine tries to feed. That round getting fed gets banged up pretty hard by the bolt lugs and becomes useless. A stovepipe essentially. Have to lock back the bolt, drop the mag and manually remove the empty brass hung up on the bolt face. The cartridge trying to be fed drops free and has locking lug dimples in it making it useless.

While at the range I broke the weapon down. The bolt face near the ejector pin and around the inside edge is colored brass. I put in an empty cartridge and it felt a bit tight. Worked the ejector and extractor and they felt OK. Cleaned the bolt face and reassembled. Shot about 20 rounds with no problem but then the stovepipes started again.

Used Federal XM193 ammo. It looked to be remanufactured as all the brass had heat marks.

Used Bushmaster supplied brand new magazine but don't see how that could be the problem.

So what gives? is the circumference on the bolt face where the cartridge base sits maybe a bit undersize? How do I fix this?

What else could be causing the problem?

This is annoying as hell - my $200 commie rifles have yet to fail - EVER! - after over 500 rounds each but my $900 US made rifle can't make it thru 80 rounds.

Please HELP! I really don't wanna have to send this thing to BM...

 

[Gewehr98]

Wait a second...

Used Federal XM193 ammo. It looked to be remanufactured as all the brass had heat marks.

You mean the color change in the brass on the neck and near the shoulder that indicates it was annealed (aka, heat-treated)? That does NOT indicate it was remanufactured, btw, far from it. Several manufacturers of new ammo, especially milspec contractors, use case neck annealing.

Dunno about the FTE's, I've never experienced them in either of my 2 AR-15's, or my issue M16A2's. People who live, breathe, and eat AR-15/M16 will be along shortly to tackle that one.

 

[Jeff White]

How is your magazine? If the feed lips are bent it may be causing this double feed. If it does it with more then one magazine we need to look at the gas system.

If it's gas system, what's really happening is you are getting short recoil. The bolt is not travelling far enough to the rear. Do you have a 16" or 20" barrel?

The first thing I'd check is the carrier key. It's the tube shaped thing on top of the bolt carrier. the gas tube fits into it. Check and see if it's loose. If so, get the right sized hex key and tighten it down. Then stake the screws in place. What happens is that gas bleeds off where the carrier key rests on the carrier and the action doesn't get enough gas to cycle all the way. I have heard of bolt carriers coming from Bushmaster with unstaked keys. I also know some people who use locktite there instead of staking the key. Specs call for the screws to be staked in so they don't loosen up and cause short recoil.

If the carrier key is tight there are some other things we will look at.

Jeff

 

[pbhome71]

It sound likes the bolt is in wrong way. But you said that it was working for 20 rounds before it happened again after a cleaning, so I don't think it is the case.

 

[Werewolf]

I will check the carrier key to see if it's tight. Short stroking sounds like it may be the problem. Won't take long to do that.

The BM mag is brand new which is why I used it but for information's sake I tried two other 30 round mags that are rebuilds. Same thing happening.

I tore down the bolt to include removing the extractor. It looks OK but there was a piece of brass in there.

Cleaned and lubed loaded 5 rounds into the BM mag, went out to a safe place and tried manual extraction. ON 10 tries 2 stovepiped on me (still gonna check the carrier key though).

Oh - it's a 20" Fluted Barrel...

As for the bolt being in backwards - how is that possible - the cam will only go in one side and the orientation is exactly as shown in the BM manual but I will double check that too.

Thanks for the feedback.

Hope this is something that's a simple fix.

Will keep you apprised. Won't be able to test fire again until tomorrow.

 

[Werewolf]

Follow up...

I think short stroking is the problem.

Carrier key was tight.

So I tried the manual eject again (5 rounds, reload mag and 5 more).

This time I made sure I charged fast and all the way to the back. No problems the cartridges ejected and fed just as they should. (maybe not a good test but it indicates that the ejector/extractor is doing what it should if the bolt and carrier go all the way back).

Checked the three rings on the bolt. Got the notches at 120 but set them before first firing anyway when I did the initial clean and lube.

I've swabbed out the gas tube on the upper with a pipe cleaner as far as I could.

Is it possible that the carrier key to gas tube fit is not good and gas is leaking by there? If so what's the fix?

NOTE:This is a brand new weapon - only fired at BM until I got it if that makes any difference.

 

[WalkerTexasRanger]

Werewolf,

I had this same problem on a brand new FN upper. What stopped the misbehavior for me was to polish the chamber. I took patch, covered it with JB bore paste, chucked a piece of cleaning rod into my cordless drill and went to town. Worked perfectly, never another FTE. Now, my FN did not have a chrome lined chamber, which if yours does, this may not help, but it sure won't hurt.

I have also see times where the recoil spring was slighlty to long and was causing the short stroking. You might just try swapping springs if you have a couple of uppers..

Let us know what you find..

Good Shooting!!!

 

[geekWithA.45]

I had this problem a while back, my formerly reliable Bushie started short stroking on me.

2 problems cause it:

1) I had experimentally lubed it with tetra grease...it's too thick. AR's need light oil. (OK, so it's pilot error there)...I'd also run into at least one other fellow who had this problem on a new AR. His gunshop took it upon themselves to clean and lube their stock, using grease.

2) The gas key had worked loose, but it wasn't apparent because some carbon/gunk had built up between the bolt carrier and the gas key.

Cleaning out the whole thing using Gun Scrub returned it to "just metal", and also revealed the loose gas key, which was easy to fix. Relube, re-assemble, and no problems.

About 500 rounds later, I had a single FTE, which I traced to gunk under the extractor. Not bad, considering I'd put about 2500 rounds through her, without ever taking the extractor apart before.

The other thing to look at is the D-Ring:

http://www.fulton-armory.com/D-Fender.htm

 

[dave3006]

I had four BMs. They all did this. They had undersized gas ports. Larry at L&G Weaponry fixed the problem.

 

[Bartholomew Roberts]

First, I'd be VERY wary of doing anything to the gas port - often what appears to be a problem with too little gas in the AR15 series is really a problem with too much gas and enlarging th port will just make the problems worse.

The bolt face near the ejector pin and around the inside edge is colored brass.

I tore down the bolt to include removing the extractor. It looks OK but there was a piece of brass in there.

This is usually a sign of too much gas, not too little. The brass is expanding back into the bolt face from a lot of pressure and heat and while it is in this semi-fluid state, the ejector and extractor are biting off pieces of the brass. Enough brass can build up to bind up the ejector when that happens.

Here is what I would do to troubleshoot this rifle. Get a box of XM193 and some cheaper ammo loaded to SAAMI specs (Winchester white box value stuff).

First, make sure it isn't a magazine related issue or gas-key is too loose. You've had the same results with three magazines, so probably not mag related; but check the mags for any obvious signs of damage or feedlip spread. Bushmaster did produce a run of bolt carriers with loose gas keys in 2003, so this is a possibility. If you have doubts about whether the gas key is tight enough, check it immediately after a malfunction, if you can noticeably torque the screws any with a hand tool - probably too loose.

However, I don't think the gas key is your problem here. If the gas key proves tight, take a look at your ejected brass from the XM193. I am betting you'll see deep "bites" on the rim where the extractor is pulling on the rim of the ejected case. Make note of it if you can see such marks; because that is important in determining what is wrong. Also look to see if the rim has been "ripped" any.

If you see those marks, immediately switch ammo to the SAAMI spec stuff and see if your problems continue with that. If the gun begins to function correctly with SAAMI spec ammo, the problem is that you have too much gas pressure in your rifle and there may be several causes of it; but all of them are solvable. If you don't see the marks, then something weird is going on; but I'd start looking at reasons why you may be getting too little gas pressure (check the gas key for partial obstructions - you'd be surprised what can get in there)

Finally, Bushmaster has excellent customer service and warranty. Unless you just want to troubleshoot this yourself, send it back to them and have them fix it - however, if you want to do it yourself and avoid the shipping hassles, I'm pretty sure this is a solvable problem.

 

[Werewolf]

Thanks Bart,
In fact on the brass there are nicks and burrs in the area that contacts the ejector/extractor parts. The failures start after about 20 rounds. If I let the rifle cool I can get 10 to 20 rounds thru it without a failure but after that it's every 3rd round or so (and sometimes every round).

I am currently using Federal XM193 Ammo. It sounds as if you are saying use some standard .223 and if the problem goes away then there's too much gas. What's the resolution to that
I'm taking the rifle out to shoot it late this afternoon. I've thouroughly cleaned out everything gas related as well as "generously" (per BM's rec) lubed the inside and outside of the carrier. In addition I lubed up the buffer spring and bolt as well.

I don't hold out much hope for the above resolving the problem though so any ideas you could provide would be greatly appreciated. I would like to avoid having to send the thing back to BM or get into a pissing contest with the shop I bought it at (since I've only had the rifle a little over 2 days now).

 

[Bartholomew Roberts]

Yeah, everything you are describing to me sounds like too much gas. It looks similar to short stroking but that is because the extractor and ejector are trying to pull the brass from the chamber while there is still high pressure in it and the brass is still expanded and gripping the chamber walls. When the pressure finally does drop enough that the gun can pull it out, there isn't enough "oomph" left and it looks like a short stroke.

I'd still try some SAAMI pressure ammo to verify that too much pressure is the problem. SAAMI is loaded to lower pressures and has a different throat, so if too much pressure is the problem, it should cycle just right with SAAMI ammo.

Assuming that the gun works fine with SAAMI pressure ammo, what length barrel is this gun? If it is a 16" or 14.5" barrel, gas pressure problems caused by the shorter gas system are common enough that there are a couple of different solutions you can try. If it is a 20" rifle, your options are much more limited and Bushmaster may be the best solution. Also, have you changed any components in the gun - what type of buffer and stock are you using? For that matter, give me a quick list of ANY changes you have made to the gun from its stock configuration (and what that stock configuration was)

Basically, it sounds like your problem is that your bolt is trying to pull the spent cartridge while chamber pressures are still too high. We want to delay the gas impulse to the carrier so those pressures have time to drop. One way to do that (if you have a carbine length gas system) is with a pigtail gas tube that increases the length the gas has to travel to reach your bolt carrier.

 

[Werewolf]

20" Fluted barrel....

Everything is stock out of the box. Purchased new at gunshop.

I'll pick up a box of .223 this afternoon before testing the thing to see if it's still hosed.

So if the standard Rem .223's work but the XM193's don't the problem is too much gas and since I've got a 20" barrel it's best to let BM fix the problem - right?

In 30 years I've never had to send a gun back - guess it was inevitable that eventually I'd get a lemon.

 

[Bartholomew Roberts]

So if the standard Rem .223's work but the XM193's don't the problem is too much gas and since I've got a 20" barrel it's best to let BM fix the problem - right?

If the SAAMI .223 works and the XM193s don't then the problem is there is too much pressure in the chamber when your bolt begins to extract.

One other thing I would look at is to try this batch of ammo in another rifle and see if it shows the same problems, or try another batch of 5.56mm NATO-spec ammo in the rifle and see if the problems continue. There is a chance you could have a bad ammo batch rather than a bad rifle. Continue to check for marks on the rim, brass on bolt face with both SAAMI and NATO ammo.

If you narrow it down to the rifle, and you already have a 20" gas system then your options are limited. You could try a heavier bolt carrier or heavy buffer to try and slow down the extraction some; but even if that did fix the problem (and I'm skeptical it would), that rifle will still be right on the edge of reliability and I would never trust it. I'd rather send it back to Bushmaster and have them address the issue of why it is trying to extract with too much pressure in the chamber.

Either you are generating more pressure in the chamber than the system is designed for (bad chamber dimensions, bad headspace) or the system is sending back too much gas to the carrier too fast (short gas system, oversize gas port). Given it is a rifle length system, I'd say the first option is more likely.

In any case, replacing the current barrel with a new (and in spec) one will address three out of the four possible causes above and Bushmaster should be able to do that quickly and get it back to you.

 

[Werewolf]

Bart - much thanks for all the good info. It has been educational.

I picked up some Winchester .223 REM in 55gr FMJ (not the military grade stuff but civilian .223) and will try it out this afternoon.

I'll let ya know how it goes (I always hate help me threads where the guy getting helped never says thanks or even lets folks know how it turns out).

Later...

 

[WalkerTexasRanger]

Werewolf,

I will add again, try polishing the chamber. If it has a small burr, or is just slightly out of spec this may make the difference. If the rifle functions fine when cool, but not when hot, then it might be as the chamber gets hot and expands that the imperfection is making the difference.

I received this fix directly from FN, and they were right on.

In my many ARs, I have noted that amlost always there is an easy fix. Try them all before resorting to complicated ones.

Given all explainations, most of time the simpleist is the truth.....

 

[Werewolf]

Follow UP:

The stovepipes/short strokes occur with two different lot numbers of Federal XM193 and Winchester .223 55 gr FMJ (walmart value pack). So three different ammo's fail. The problem appears to be getting worse. I didn't even get thru 10 rounds this afternoon before the first stovepipe.

Based on that and all the other information I've received I'm going to assume low gas pressure though a tight chamber may also be the problem.

I'll be taking the gun back to the shop tomorrow. They can fix it or send it back to BM. What sucks is that for $900 one should expect to get a working weapon. I'm totally bummed. This problem should have been caught at BM - 20 rounds is all it took for the problem to show up the first time.

WalkerTR: Good suggestion about the chamber but I have neither the tools, the skill nor most importantly the confidence to take on a job like you've described. Good tip though - thanks.

 

[WalkerTexasRanger]

Where in OK you from? I am from Ponca City originally...

All it takes is a part of a cleaning rod, a cordless drill, some JB paste, and a couple of oversize patches. Just chuck the rod into the drill and put on a plastic tip, likes comes with some cleaning kits. Coat the patch in JB, insert it into the chamber, it will not go into the bore if oversize, and crank up the drill. Polish away. Pretty easy really.

I completely understand your frustration. When was having the problem I was not happy....

 

[Bartholomew Roberts]

Walker, that worked in your rifle because the chamber was not chrome-lined. If a rough chamber is part of the problem here and the barrel is a Bushmaster, then the roughness will have a layer of hard chrome plated over it that will make your polishing less effective.

Werewolf, hey, that could actually be good news as that problem is easier to fix. Just a quick check; but is the barrel of this rifle marked "B MP 5.56 NATO 1/9 HBAR"? It should be marked on the top of the barrel in front of the front sight base.Also, see any unusual wear in the upper? Anything that might stop the carrier from moving all the way back?

I'd second sending back to Bushmaster. It may be one of the run with improperly secured gas keys and you are leaking gas there. Anyway, let us know how they handle it and if they make it right for you.

 

[Werewolf]

Just a quick check; but is the barrel of this rifle marked "B MP 5.56 NATO 1/9 HBAR"?

Yep! That's exactly what it says. Is that significant in some way?

see any unusual wear in the upper? Anything that might stop the carrier from moving all the way back?

Actually on the bottom of the carrier there are some wear marks on one side of the center rail.

I'm taking the weapon back to H&H tomorrow and will have them send it back to BM for me.

Thanks for all the help guys - I really appreciate it.

Unfortunately even if BM makes the rifle perfect I will be soured on them forever. I managed a Quality Assurance group for 6 years. Some things get by good QA but IMHO this problem never should have gotten out the front door. Very annoying. Not good for repeat business no matter how good their customer service is.

 

[Werewolf]

Where in OK you from? I am from Ponca City originally...

WalkerTR - though I've lived in OK for the past 16 years I was born in TX and spent about 2/3 of my childhood there (Houston, Amarillo and San Antonio). The other 1/3 was spent overseas as a military dependent.

After leaving HS and joining the military I spent the next 13 years happily traveling around the world on Uncle Sam's nickle before finally getting married, getting out of the service and moving to OK where I've been ever since. My hardcore Texas mother is probably gonna turn over in her grave and haunt me for this but I'm more Okie now than Texan, I'm an OU graduate and root for them every year when they play UT - oh crap! what's that sound? noooooo - mom I didn't mean it. please noooooo!!!

 

[ny32182]

Very annoying, and I may very well have felt the same way, but everyone gets a bad one out at one time or another. Thats just how it works.

Bushmaster does the most civilian sales volume by far, IIRC. I've got two, both flawless. IMO, no one has a better civilian AR offering.

Let us know how it pans out with customer service; I'd like to know what to expect in the event that I ever have to deal with them. Good luck.

 

[Werewolf]

Some of you who helped me with the problem my BM had asked for a follow up so here goes.

I finally got my Bushmaster XM15E2S back after exactly one month from the date I dropped it off at the gunshop where I bought it new.

They sent it to Bushmaster who repaired the thing. The weapon now feeds, extracts and ejects flawlessly.

BM said the problem was with the bolt but that was as specific as they got. Why they can't provide more detail on a repair ticket is beyond me. I had the shop gunsmith call and query Bushmaster and they wouldn't provide anymore info than was on the ticket. I wonder what they're hiding?

A thorough examination of the weapon after I got it indicates that they probably changed out the ejector pin and/or the ejector pin spring. Prior to sending it off the ejector pin was very, very difficult to press in using the brass case under extractor roll test. Now it operates very smoothly so I strongly suspect this was the problem. Considering the nature of the problem ejector pin jamming up makes sense. After about 10 to 15 rounds (and subsequent heat up) the weapon stovepiped. Heating up the bolt may have caused the ejector pin to swell and thus cause it to operate ineffectively.

My only real concern with the weapon now is that the rear sight must be set about 75% to the right for me to shoot on center. This may be a function of the way I'm holding the weapon, sighting etc or it may just be the weapon. I'm going to have my daughter try it out and see if she shoots right of center. If so it's me if not then either the front sight post is mounted too far right or the rear sight assembly is too far left. Not a big deal but annoying. (since the rear peep sight is an out of round blur to me I'm thinking I need a new glasses prescription and that may be the problem)

I've put about 200 rounds thru the weapon and I must say it doesn't feel anything like the M16A1 I used in the Army. It's much heavier and the recoil is surprisingly much greater. Maybe the recoil feels heavier because with the M16 I was young, in shape with well toned muscles as opposed to now being old, out of shape and with flabby muscles. It could also be that (IIRC) when I was serving the ammo we used had a 40gr bullet and exited the muzzle at around 2700FPS vice the current 55gr bullet at 3050FPS. Still the recoil is much greater than I expected and the flash is way more too. It's not blinding during the day - just annoying - but made me see stars at night. Of course that's because there's no flash suppressor on the the weapon. When the AWB expires a flash suppressor is the first thing I'm going to add to the weapon.

My AK and Saiga are much more fun and easy to use than the AR-15 and without the annoying flash (at least I don't notice it on them). Disappointing really but hopefully as time goes by and I refamiliarize myself with the AR things will get better. I hope so - $900 for a gun I don't like vs $200 and $350 for two I do. Doesn't say much for US weapons.

 

[ny32182]

Glad to hear Bushmaster cleared it up for you.

I don't _think_ there was ever a 40gr round issued (55gr is the lightest I ever heard of.. 55gr M193). One other difference is that the flash suppressor on your issue weapon probably helped to tame the recoil a bit, and if your Bushy has a bare muzzle as many post-ban guns do, it will have more recoil than a gun with a break of any sort. Many, many AR's have to have the rear sight adjusted in order to be on target for most people as well.

If you still decide you don't like it, I'm sure you could get at least 700 bucks selling it.

 

[iamkris]

Bartholomew Roberts

You mentioned above that "If it is a 16" or 14.5" barrel, gas pressure problems caused by the shorter gas system are common enough that there are a couple of different solutions you can try."

I have a new Model 1 16" CAR upper with chromelined bbl and chamber on a DPMS lower. 2x out of 60 rnds of Spanish SS109 fired I've had FTE. I've not had a chance to fire any other ammo. In both instances, the empty case was stuck in the chamber and the rim was ripped off. Does this sound like the "too much gas" problem? Certanly not as bad as Werewolf's problem, but concerning none the less.

If so, what the the "differrent solutions" I can try.

Thanks in advance.