Suggestions on a BCG malfunction?

Discussion in 'AR15/10 Rifles' started by BigAndy, Mar 12, 2013.

  1. BigAndy

    BigAndy Well-Known Member

    Messages:
    72
    Joined:
    Jan 17, 2012
    I bought a Fulton Armory chrome BC and my bolt won't cycle. It seems to get stuck and not unlock. I know the gas system is right and my bolt is mil-spec. The rifle works with other bolts. The problem is FA shut off their phones and won't answer any of my emails. Do you guys have any suggestions? It's really a pain because everything else is finished on this build, but carriers seem to be out of stock or way overpriced everywhere you look. Sorry for the ramble, but your thoughts on the matter are appreciated. Thanks.
    -JA
     
  2. ICANHITHIMMAN

    ICANHITHIMMAN Well-Known Member

    Messages:
    4,380
    Joined:
    Jan 31, 2008
    Its not mil spec, that's just advertising. Is your lower and older colt by any chance? You most likely have some thing up in the barrel recess. If its not a colt lower and your sure every thing is where is supposed to be? Then shotgun that weapon!

    Grab it like you going to butt stroke some one and slam the butt stock into the ground until the bolt comes free! I had this happen in a no shit situation once and believe you me it will work!
     

  3. woodnut

    woodnut Well-Known Member

    Messages:
    344
    Joined:
    May 5, 2009
    I had a similar problem with another brand. I found another thing could cause the lock up. Reloading with a too long bullet. Or, just a bullet seated too far out.
    Did your bolt fully close and were you able to fire the round? If not, it very well could be a long bullet running hard into the lands causing the bolt to not go fully home and then... it's stuck. That's easy to find; just run a round home and try to extract it without firing. If you can, that probably ain't it. Do it again and try to fire it. If it didn't go fully into battery, it shouldn't fire. Then ..I don't know.
    Icanhithimman is correct; and it won't hurt the stock to do it either. I like to put my foot on the charging handle release and then lift the rifle and punch it into the ground, butt first. Your foot will add pressure to the bolt and it will open. Maybe not the first time, but it will open. Won't fire, but still keep yer head out of the way. This way isn't as shocking to scopes.
     
  4. BigAndy

    BigAndy Well-Known Member

    Messages:
    72
    Joined:
    Jan 17, 2012
    The rifle does fire every time, but just doesn't cycle. I essentially built a bolt action AR. The charging handle is hard as anything to pull back after the round fires. The lower is a DelTon and the upper is a DPMS lo-pro. I added a DPMS Mark 12 barrel with a free-float tube (screw-on, not clip-in). Next range trip, I will slam the buttstock as mentioned above. Thanks again fellas.
    -JA
     
  5. c_bass16

    c_bass16 Well-Known Member

    Messages:
    457
    Joined:
    Sep 22, 2009
    That sounds like more of a gas problem than anything. The reason it's hard to extract the spent round after it DOES NOT eject, is because it expanded in the chamber without rearward extraction at the same time.
    Pivotal for proper extraction.
     
  6. BigAndy

    BigAndy Well-Known Member

    Messages:
    72
    Joined:
    Jan 17, 2012
    I guess I will double-check the BCG key/gas tube alignment tonight.
     
  7. msalm

    msalm Well-Known Member

    Messages:
    225
    Joined:
    Jul 18, 2007
    Did you just replace the carrier, or the bolt and carrier? Not sure on FA, but some of the chrome plated carriers start as standard carriers, then are plated so their dimensions may be a bit larger than a standard one. #1 , disassemble the bolt and carrier and just slide the carrier in and out of the receiver with your finger and see if anything sticks with just the carrier. Try and troubleshoot one component at a time, the gas tube might be sticking in the carrier key, although if that's the case the rifle will normally still function. If the carrier slides in and out w/ no problem, install the bolt with cam pin and cycle that by hand (this is all with the upper/lower separated). You should be able to push the assembly all the way forward, and retract it w/ just your finger in the back of the carrier. It sounds to me like a tight headspace issue along with a faulty gas system somewhere, maybe a plugged carrier key.

    Oh, and if the bolt is also chromed, the headspace may be too tight as their tolerances are also different from the chrome plating.
     
  8. ICANHITHIMMAN

    ICANHITHIMMAN Well-Known Member

    Messages:
    4,380
    Joined:
    Jan 31, 2008
    If it where a gas issue the bolt wold still open. It sounds like a lot of things could be wrong. Starting with the gas tube to gas key fit. I have also seen some bolts that could be assembled backwards. There may be something under the hammer not letting it close. If other bcgs work in the rifle then we have to look at the bolt.
     
  9. woodnut

    woodnut Well-Known Member

    Messages:
    344
    Joined:
    May 5, 2009
    MSALM has very valid points. I just ran across a guy who's new AR would short cycle. Finally found blue locktight in the gas key! Seems the company guy staking the key wanted to make sure the screws wouldn't walk and got some down the tube by accident. Cleaned out and function restored. MSALM says to take it one component at a time; sage advise. Be of good cheer, you will find the source of the problem and I bet it's simple to fix! It just may take a bit of looking and testing. You've got good resources in MSALM and ICANHITHIMMAN. Trust them.
     
  10. acloco

    acloco Well-Known Member

    Messages:
    502
    Joined:
    Jul 1, 2006
    This is not an unusual problem.

    Literally, just finished helping out a friends AR tonight.

    #1 - LUBE the buffer tube, spring, and buffer. Lube the tube, outside of spring, outside rear of buffer (slides on the inside of the spring), and the large rounds of the buffer. I HIGHLY recommend STOS from Ponsness Warren - 100% synthetic, does NOT sling, and lasts a long time. A little dab will do you.

    #2 - Polish the chamber! Flitz or other NON gritty metal polish on a shotgun bore mop with a low speed drill is nothing short of wonderful. DOWSW with carb cleaner (pull the gas block first).

    #3 - lube the BCG. Again, a dab here and there...and manually cycle the bolt when it is out.

    #4 - ammo - if you are reloading, 16" barrels, generally operate better at max loads.
     
  11. woodnut

    woodnut Well-Known Member

    Messages:
    344
    Joined:
    May 5, 2009
    Acloco is right on; but heed his advise that a little dab WILL do ya! Some even say to use a very light oil for this. If it's too much of any lube; it will attract dirt and can retard function. Neither are good things. But do lube it. The polishing of the chamber is very good,too. When you lube the BCG, I use a light oil just before shooting and lube each lug of the bolt and a little dab on the carrier sides. The wear areas. After cleaning the rifle and BCG; before I install the bolt I lube the gas rings, just behind the gas rings, the cam pin, and around the ejector. I also lube the firing pin for the same reason, and all this oiling also helps cleaning the carbon off. Rub around with a finger to spread it overall. LIGHTLY! Except the lugs, I keep them wet. It will smoke at first shot or two, but it is a good thing. You may also want to look into a flat chrome silicon buffer spring. You won't buy but one, they last.
     
  12. ICANHITHIMMAN

    ICANHITHIMMAN Well-Known Member

    Messages:
    4,380
    Joined:
    Jan 31, 2008
    Your both way off, lube will not retard the function in any way what so ever the more the better! AR are meant to run WET not dry if you think your adding to much add more! If the BCG does not visible look WET you don't have enough on there! This issue has persisted since NAM and I'm not sure it will go away anytime soon. Lube your BCG then lube it some more and then more, the biggest cause of malfunctions in this system not related to bad mags in not enough lubrication.

    "The golden rule in weapons lubricant is you can run a gun dirty and wet, but not dirty and dry" LAV
     
  13. woodnut

    woodnut Well-Known Member

    Messages:
    344
    Joined:
    May 5, 2009
    ICANHITHIMMAN, I should have said keep the recoil spring lightly lubed, oiled actually is best. But I agree, wet the BCG ! I actually greased my recoil spring too much and it did, in fact, retard the action. Cleaned it up, left a film on it and it runs properly now. I do run all my BCGs wet- wet.
     
  14. acloco

    acloco Well-Known Member

    Messages:
    502
    Joined:
    Jul 1, 2006
    If we were still living in the previous century you would be right.

    It is ok to try something new.