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Posted: 1/20/2008 9:46:23 AM EDT
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I bought a Bushmaster Predator with 20" barrel two weeks ago and from the getgo I have had FTF problems. I have used four different high quality brands of .223 ammo and three different magazines. I contacted Bushmaster about the problem and they gave me a few things to look at and try so I did. 1. Check the bolt carrier key screws...They were tight. I took the key off and used some blue loktite around the gas hole to seal it. 2. Check the alignment of the Gas Block...I did and it seemed to be aligned properly so I re-installed it. 3. I checked the gas rings on the bolt to see if the gaps were all ligned up and 2 of them were so I offset them and re-assembled. After a good cleaning I went back to the range and the same FTF problem showed it's ugly face. It would feed the first ten or so rounds and then stop feeding. I then sent the whole gun back to Bushmaster and they had it back to me in 2 days. I took the gun back to the range after re-mounting my scope and it shot fine (only 1 FTF in 60 rds). This weekend i took the gun coyote hunting and it stopped feeding AGAIN! This gun should not be affected by the cold should it? The temp was -4F. Any suggestions would be greatly appreciated. |
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What ammo are you using? Are you using a chamber brush to clean the chamber, and completely removing all the copper solvent from the bore/chamber before putting the rifle into action? Are you lubing the upper bearing surfaces, including the buffer and recoil spring, with CLP? www.ar15.com/forums/topic.html?b=3&f=7&t=203988 P.S. Welcome to the site!!! |
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1. I have tried Remington 55. gr AccuTips, UltraMax 55 gr. NBT, American Eagle 55 gr. HP, and now I am using the Black Hills Ammo 55 gr. SP. 2. I have used three Bushmaster clips 1-5 rd and 2-20 rd. After reading as much on this site as I could find that related to my problem I tried the only thing I hadn't tried yet and that was the BF CLP and the BF bore scrubber. I used a chamber brush and fully cleaned every surface of the gun. I shot the gun today and the first three shots went bang bang bang and then click. Did not strip a new shell. I manually charged it and it went bang click. This time it was a three point JAM. After ejecting this shell the rest of the 20 rd clip fired fully. I put in a new clip and it shot the first four and then had another three point jam followed by three FTF in a row. Then fired the rest of the clip fully. If I didn't mention I am shooting in sub-zero temperatures, is there another product I should use to clean the gun that is better for extreme temps? Would a H-Buffer help or hurt? Again keep in mind the cold temps. Thanks again for the help...this is by far the most informative site I have found. |
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Are the 20 rounders straight mags, or curved like a 30 rounder? The 5 and 10 round mags have been known to be problematic, and so has the curved 20 rounder as well. Worst case, buy a few 30 round USGI mags (can be found in the EE new for under $15. each, and you will never have enough mags) and see if new USGI mags solves the problem. On the two rounders, pull them apart and give them a good CLP cleaning, along with checking the skirts of the followers for casting burs that need to be cleaned up (read just use a knife). It sounds like these mags are just production dirty, and have not broken in yet (follower to the inside of the bodies causing a feeding/ top round recovery jams). |
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I found my self having the same problem with my Bushmaster 20" predator. I found its short stroking, I'm using 55gr fmj Remington ammo, I have less than 200 rounds through the gun and it keeps getting worse. I mean to say I'm having to cycle the charging rod after every shot. I called Bushmaster to day and talked to one of there Seinor Gun smiths. He said to remove the bolt carer group spray some light oil like "WD40" or spray gun lube (I'm willing to bet CLP will work). Then get a small tube that will fit over the key and holding the bolt in the locked position and blow in to the tube. What your looking for is any bubbles and or oil coming out from the key and the carer group. He said if it is leaking oil pill the bolts out of the key mounting and clean where the key and the carer group meet. He said to use "Lock tight" on the bolt threads and tighten with a allen wrench by hand, and retest. If that dose not fix the problem send it in to Bushmaster. I'm gonna try this later and see if it care of the problem. Hope it helps you. Brett |
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Check out this video of the FTF. 100% failure. www.youtube.com/profile?user=cdanforthc |
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The rifle is short stroking!!! Start off with the gas system and check for leaks. Check the condition of the chamber. Is it reamer marked or the plating rough? Check the back of the trigger and disco tail for dents marks that would indicate that the hammer is wedging at cycle. Pull the buffer and check the bumper roll pin to confirm it's not protruding and catching the spring, and on the spring, check the ends of winds for burs that may be scrapping down the inside of he tube. With the upper open, point the muzzle 45* downward, stick your finger in the center of the carrier, pull back on the B/C until it reaches the charging handle, then let the carrier go. The B/C should glide back down on it's own weight with the bolt locking up. As for the spent cases, some appear to be really fouled, and the rifle looks/sounds dry as hell. Are you correctly cleaning the chamber with a chamber brush and copper solvent (remember to remove all the solvent) and lubing the upper bearing areas, including the buffer and spring with CLP. Hate to say it, but think that your problem could be solved with nothing more than a spray can of BreakfreeCLP to lube the rifle and allow the rifle to break in correctly (read pull the B/C out of the rifle, spray it hard inside and out with CLP, give the B/C a quick single flick to knock off the excess CLP, then stick it back in the rifle to retest). |
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Dano523 When i hold the upper at 45 degree and let go of the BCG it slides into place and locks with no problem. I have had the buffer out several times to check for protruding pins or wear marks and found none. Last week I sent the whole gun back to Bushmaster and they sealed the gas block and polished the chamber. I have now tried Hoppes gun oil, Rem Oil in spray can, Rem Dry Lube, and BreakFreeCLP and bore scrub. I have a brush kit with a chamer brush, upper brush and BC brush that I use every time I clean the gun. As far as the amount of lube to leave on the gun, should everything be dripping wet? I just find it hard to believe that this "Military Spec built" rifle should need this much lube. We have guys in Iraq that are shooting several hundred rounds a day in the sand and 100 degree plus heat, their rifles shoot no problem. If I have to lube this thing until it is dripping wet to get it to shoot I feel I am just masking a problem. I just was told by the engineer at Bushmaster to degrease the whole gun to remove the BreakFree and to use the Rem Oil in the spray can to lube it. I did so last night and left far more of the oil on the gun than I would with any of my other guns for fear of dust collection. I took it to the range and 100% failure again. This time to the range I shot the last of the 500 rds I got when I bought the gun. Shouldn't 500 rds be enough to break it in? Thanks for your tips, keep them coming something has to work. |
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Read these primers: TM 9-1005-319-10 Operator's Manual w/Components List M16A2, M4, M4A1 Cleaning & Lubricating an AR15 Rifle Of the 4 types of ammuntion you stated, I would only call Black Hills high quaility, but then you might have a difference point of view in this regard. Bushmaster is not a "Military Spec built" rifle, but this should not matter to you. And yes, you should lube your rifle. Running your AR dry is the fast path the jamville. Nobody who actually uses their Rifles/Carbines in the GWOT runs it dry. Lubes and Oils seem to be very personal. I have used FP-10 since I was a PFC at AMTU at Ft. Bragg, but Break Free CLP works very well. Never used Rem-Oil for anything, so I have no opinion on it. Start at the front with the Shaved Front Sight Base and see if it fits on the barrel tightly and that there are no gas gaps, then move rearward to entire Bolt Carrier Group. 
Red Locktite is what you should have used. Did you check to ensure that the Carrier Key was straight and true? Did you lap the key if it was not? How did you restake the Key? Did you peen the key to remove any burrs from the re-staking process? If you did not do this correctly, you might have to buy another carrier key and install it correctly.
This is not that important, but still, if they are staggered, then this is a non-issue
Did you lube your AR? I do not mean a drop or two, but did you REALLY lube it?
NO!!!!! The H, H2, and H3 buffers were to be used with a Carbine Buffer Tube. If you use these in a Rifle Buffer Tube, you will damage your Bolt Carrier and your lower. What type of stock do you have on your lower?
Maybe. The cold temps could have the effect of making your AR short-stroke, if it is not getting enough gas. |
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RedFalconBill: Thank you for your input and please read the following.
I spoke with a Bushmaster rep yesterday and asked him this question and he informed me that everything behind the barrel IS built to military specs. I'm not an expert by any means...this is just what I was told.
I lube this gun the same way I lube all of my guns including my Benelli Super Black Eagle II semi auto shotgun and that works in sub-zero temps filled with slough water and mud. I know that the Benelli is inertia driven and the AR is gas, but there are just as many moving parts and just as much friction created.
I removed the key just as I said and tried the rifle after I re-set it. When that didn't work I sent it in to Bushmaster and they re-sealed the gas tube, re-aligned the gas block, re-set and staked the carrier key, and polished the upper to remove any burrs.
As I posted above I did lube the gun. I lubed it from a light coat to almost dripping. There was no change. The reason I made the comment about the soldiers lubing their rifles is that I can't imagine them stopping in a heated situation to clean and lube their guns. I can't get a full mag to fire from mine when it is spotless and dripping with lube. If it takes a gallon of lube to get this thing to cycle then the lube is just masking an underlying problem that will come up again in the future when I need the gun to perform. |
A Barrel does not make a rifle. Yes, they use 4150 steel in making the barrel. This does not mean much, but it does make for good marketing, though.
You should not treat every firearm the same.
Hummm?? Did they test fire it? If so, what ammunition did they use and what issues, if any, did they have?
Very true. It sounds that due to the cold temps, your Bushy is having gas issues. Whether this is due to a gas leak(s) somewhere in the system, not enough gas coming back, underpowered ammo, lube turning to guck due to cold, some combination of the above, or something else entirely, I cannot say. Best I can say is to look at the dash 23 to troubleshoot further. TM 9-1005-319-23 Unit And Direct Support Maintenance Manual M16A2, M4, M4A1 |
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RedFalconBill: you seem to be very experienced with ARs here are a few questions I have for you that maybe you can answer for me. 1. I know that it is not recommended and you should never do it but with that in mind should a properly functioning AR fire 20 rounds with no lube at all? 2. As far as the ammunition is concerned if the rifle is working properly it should be able to shoot any commercial ammunition...right? I'm not saying that you can go out and shoot 1000 rds of dirty ammo flawlessly with no cleaning, but a well lubed well taken care of rifle should have little or no malfunctions off of 99% of the ammo on shelves today...or am I wrong? |
Experienced, me?  Hardly. Thanks for the complement, though.
Well, depending upon the ammuntion being used, yes your Bushy should be able to fire 20 rounds w/o lube. But why?
Commercial Ammo? It depends. SAAMI spec ammo is NOT loaded as hot as the M-193/M-855/M-262 ammo. With that said, yes commercial ammo should work fine in your Bushy for the life of your rifle barrel. The steel cased, Made-in-Russia, ammo does have problems due to steel not being as elastic as brass, and allowing gunpowder residue to reside in your chamber. The solution to this is not to switch back and forth from this ammo, to other types, or to use the steel cased ammo last, then clean your barrel/chamber. Earlier, mod Dano523 asked you to take your Fire Control Group (aka Hammer, Trigger, and Disconnector) to look and see if it is having issues with peening. You might also be having issues with the AR hammer and the Bolt Carrier that Bushmaster uses. Which one of these three Bolt Carrier Groups does yours look like? 
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OK the reason I asked about firing 20 rds with no lube is to rule out any thoughts I had that I am not lubing enough, or using the wrong lube. Mine, soaking with lube will not fire 20 rds w/o malfunction. To answer your other question my BCG is the Enhanced AR 15 you show here. Also I'm not sure what you mean by peening. Is this just rubbing or scraping? Are those USED BCGs you pictured? If so I'll send you a pic of mine, there seems to be more wear marks on the bottom of mine where it would ride over the mag. |
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Here are a few pictures of mine. Does this seem to be excessive wear given there are only around 500 rds through it? http://a271.ac-images.myspacecdn.com/images01/9/m_f5a7c1cbf85797a5e9d0781e71feab86.jpg http://a433.ac-images.myspacecdn.com/images01/57/m_b79559b55f9a080088a764d260cccf60.jpg http://a639.ac-images.myspacecdn.com/images01/36/m_f3e4cef479ce5ef8ea8777baa66b59ce.jpg http://a182.ac-images.myspacecdn.com/images01/124/m_8a0e9a9a1b26d748411e9bff44308335.jpg |
Heck yeah, 20 rounds is nothing. I wanted to run an upper until it choked just to get an idea of how long I could go without needing the forward assist. Started off with a properly lubed carbine, freezing temps, Wolf ammo, and a suppressor to blow back as much crud as possible... it fired 250 rounds without a failure. The lube appeared mostly gone after firing 100 or so rounds, and by 250 I called it quits because that sucker was bone dry. The 'after' pics:   Edit to add: wear on your carrier looks normal. An AR should be broken in after 500 rounds... still sounds like a gas problem. |
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WOW gregw45 if your's can do that, being that dirty and dry there is no reason that mine shouldn't fire in the condition it is in. Looking at your pics it looks like your gas tube may be longer than mine is. Can you measure how much of your gas tube you can see inside your upper for me? |
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First off, there is no mil-spec for any semi auto rifle, nor semi auto parts, including a semi lower receiver. Granted that you can get close in regards to some parts that are not interchangeable, there is just no spec for such. Do not compare a civilian rifle to a government dimensioned/ inspected rifle. Hell to take this even father, in regards to a mil-spec rifle, the barrel is the heart of the mater with the other parts behind it all functioning off of it. Yes, I can take a Colt/FN M-16 and run it dry right out of the box (after cleaning the production grease out first), and it will run for some time before it chokes (read more that a few C mags). Can you do this with “some” civilian rifles as well, yes; some are close enough in regards to mil-spec dimensions of parts (chamber/gas port dimensions/conditions being the big items here) to allow such, while other units will not do this. Do you want to run a weapon dry, no; you have parkerized parts tracking anodized parts and the bare surfaces against each other will just wear the mating parts out faster. So to regroup a bit and get back to the problem at hand, let start back at the beginning to at least confirm that the rifle is correctly stroking. Will the bolt lock back when you load a single round into the freshly cleaned rifle, charge and fire the round from it? If it will do this, then is the jam/feed problem with just the tip of the bullet just starting up the feed ramps and the B/C stuck (read can not use the forward assist to get the bolt to close the rest of the way? |
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My friend is having the same issues on a stag lower, and bushmaster 20" upper, and a generic el cheapo collapsible stock/buffer/spring. When I pull on his charging handle, it feels like there is resistance in the buffer tube. Almost a gritty/sticky sensation. Could that be the issue? |
Full length spring in the carbine stock would cause the last bit of the CH pull to be gritty/harder than the middle part of the stroke. Burs on the end of spring or the buffer roll pin extruding to far out of the buffer will cause the spring to scrap down the inside of the tube/ buffer roll pin to scrap down the spring. Also, a hammer tail that is too long will cause hammer wedge, and the middle/last part of the CH pull will be gritty/harder than normal. |
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replace the buffer spring. I have a Bushmaster AR15 and i was having the same ftf problems with 55gr ammo. I called bushmaster and they said to replace the gas rings and check the bolt and bolt carrier over again. I really didn't think that the gas rings were the problem so i took it to a local gun smith and all he did was put in a new buffer spring that wasn't as strong and then went to go fire 2 30 rnd mags through it and it was fine. I would say thry just putting in a weaker buffer spring and maybe even a lighter buffer before messing around with the bolt and bolt carrier edit: For me, i wasn't ever loading my mags to full, only occasionally, most of the time i was doing 5-10 rounds, and maybe a couple times i was doing 20, but i've never really done a full 30 round magazine. |
| My Bushmaster is 2 months old, and a bit different than yours, but I have had the identical problem on and off since I bought the gun. After many, many troubleshooting efforts I have found one common thread: if I load the mags to full capacity (all my mags are 30 round), and use non-premium ammo I can duplicate the problem. But, if I load something on the order of 15 rounds of non-premium ammo (Wolf steel case 55 or 62 grain) I can usually cycle them all without a problem. Likewise, I can load 30 rounds of premium ammo and again cycle all 30 without a problem. While this may be classified as a 'work-around' it is something that I understand and can rely on when I really need the gun to operate properly. |
From TM 9-1005-319-23 on this site: RIFLE spring should be 11.75" to 13.5" long CARBINE spring should be 10.0625" to 11.25" long Here is Russell's Buffer/Spring Chart. 
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| After I posted my reply yesterday I thought I should make sure that my 'work-around' still held true. I went to the range, and sure enough I could load a 30 round clip to capacity with premium ammo and it fired without fault. But, in order to get the same results with inferior ammo (Wolf 55 and 62 GR steel case non-corrosive boxer primed; purchased last week from Sportsmans Guide) I had to limit my mag load to something less than 15 rounds. Go figure. |
According to: http://www.ar15.com/content/manuals/TM9-1005-319-10.pdf p.28, -4F is out of bounds of operation with CLP used as lubricant. For temperatures below Zero F, you should use L.A.W. Lubricant, Arctic, Weapons. oil only. Let's face it your Bernilli receiver is probably all steel construction. The AR receiver is steel running in aluminum. Loss of clearances due to differential thermal expansion at -4F is going to show up problems unheard of in Iraq, particularly when the lubricant viscosity thickens considerably. This is one case where it might be better to run dry. All the moisture H2O in the gases being ejected back into the action from the direct impingement gas flow is going to freeze. Did you speak with Magpul about running their mags in -4F? They are sharp people and may have some other insights into running AR's in arctic conditions. You are accustomed to operating in the -4F climate apparently, so try some homebrew solutions to your lubrication. What do you use to keep door locks from freezing, engines from seizing, etc.? I don't know what L.A.W. is made of. If you can find a chronograph that will even work at those temps, try some XM193 rounds across it and see what the velocity is compared the standard 3250 fps. I think you will see a marked decrease in speed indicating lower gas pressures, which means even lower in the bolt cycling action. |
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Well, scrap everything that I condidered to be a 'work-around' or a partial solution to my Bushmaster FTF with Wolf steel cased 55 / 62 grain ammo. I went to the range yesterday with great confidence in my troubleshooting and solution(s). So there I am with 5 mags loaded with 12 rounds each of Wolf 55 / 72 grain steel case cartridges. Not a damn one of them would feed; i.e., charged, one shot fired and---click. I then loaded a clip with pricey Remington brass cased 55 grain to full capacity (30 rounds), and the little carbine sent a round down range as fast as I could pull the trigger. No more troubleshooting, no more work arounds, no more Wolf--while brass cased ammo might send me to the poor house, it's a hell of a lot more fun at the range. Signed: Soon to be broke |
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