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Help fixing my M&P 15t

Discussion in 'Maintenance & Gunsmithing' started by twoclones, Sep 4, 2010.

  1. twoclones

    twoclones Tri-Cities, WA Well-Known Member

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    My S&W "AR" M&P 15t jammed a dozen or more times today and I need help curing it. It worked fine the first 60 rounds but jammed frequently after that with both AR Stoner and Pmag magazines and PMC ammo.

    Each time it jams, pulling the charging handle back and releasing chambers the round. If I look at the jammed round, the point appears to be caught on the loading ramp(s). I clean all my guns after every use and wonder if a better job could be done on this area with some special brush... I've been using a toothbrush shaped brass brush up until now.

    Will lubricating some area help?


    ar15_loadrampdirty.jpg

    ar15_loadrampclean.jpg
     
  2. Gouki

    Gouki PDX New Member

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    What kinda magazines are you using?
     
  3. bnr32gtr

    bnr32gtr Vancouver, WA Member

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    Same thing was happening in class last weekend. LUBE THE **** OUT OF IT and you should be good to go. Try some CLP or RemOil. Spray the gas rings, charging handle, bolt carrier and inside of the upper receiver really well.

    You can't really have too much lube on an AR. Good luck!
     
  4. Bhowe

    Bhowe Seattle Member

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    Try different mags. sometimes they can get bent lips at the top if you keep them fully loaded for long periods of time. Also, a chamber brush, and gas tube cleaner would be good tools to have. Try to find a handle like the one you would use for cleaning your barrel, but you want one that doesnt have a freely rotating handle (if that makes sense). They make a flexable rod for this but is still a pain to try to use properly. Make sure the splits in the gas rings do not line up or you will loose gas pressure and the action will short stroke, which could also cause what sounds like is happening. Two other important questions are what kind of ammo are you using, and do you know if the gun is completely factory? or one that somebody assembled from parts (I assume because you said it was the T model, it is 100% factory). As far as lube goes, you don't want the thing dripping on you while you are trying to shoot, but it is also important to make sure all nessecary parts are kept oiled. I always liked the method of dunking parts in CLP and giving a light blow with an air hose to eliminate any messes. Ideally, the goal is to have a light sheen of oil on all internal surfaces, especially moving parts like bolt and carrier.

    If none of these are the issues and nothing helps I would send it back to Smith which you can do yourself, and they can ship it right back to you usually.
     
  5. twoclones

    twoclones Tri-Cities, WA Well-Known Member

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    Stoner and Pmags. The Stoners are new...
     
  6. Silverbullet-2

    Silverbullet-2 Issaquah Member

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    I would start by getting a lug recess tool from Sinclair.com. (An accuracy mail order place) The barrel extension area that the bolt rotates to lock up, look really dirty. It should be squeeky clean, and lightly lubed. A chamber brush with a non-rotating Dewey rod (about 12" long or so) will get this area a good bit. Like BHOWE mentioned. Also a rifle craddle with a Sinclair cleaning link that keeps the action open to use a bore guide would be a good idea. Used mine today, in fact. All this will get you all clean. Now use good ammo in mags that are marked, like with your name, and mag number. Keep track what mag you had a FTF or FTE. (failure to feed, failure to extract.) The ammo I use is LC 5.56 with 62 grain bullets, just like our boys in the sand box. The higher preasure will cycle your action very well. Some of the 55 FMJ stuff is loaded lightly, and will cause issues. Good luck, JPG
     
  7. twoclones

    twoclones Tri-Cities, WA Well-Known Member

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  8. sprice37

    sprice37 Albany Oregon Active Member

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  9. twoclones

    twoclones Tri-Cities, WA Well-Known Member

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    How could I tell if my gas block was loose?

    On investigating the carbon scraper tool, I found this one which looks easier to handle and costs less than half as much. Anyone have experience with it?
    KZ M4CRST Carbon Removal Super Tool

    I also found this video on cleaning the bolt and carrier. It's a Young Manufacturing chromed bolt and after 200 rounds, it's so clean (compared to mine after 200 rds) that I wonder it it wasn't cleaned before the video was made. Are these really that good at staying clean??
    YouTube - AR15 Bolt disassembly
     
  10. Silverbullet-2

    Silverbullet-2 Issaquah Member

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    I like that tool, but would advise against ordering from Botach Tactical. If you like great customer service, look elsewhere. Just my .02, JPG
     
  11. bnr32gtr

    bnr32gtr Vancouver, WA Member

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    Too much diagnostics for something that lube will fix. I took a class where this was happening to about 4 of us last weekend and Super Dave Harrington told us to lube the CRAP out of our guns. Fixed ALL THE ISSUES.

    Start with something simple before condemning the gun, Smith, mags, ammo, etc.

    Again, start with lubing the HECK OUT OF IT and go from there. Do not concentrate on the big stuff and all the special tools yet.

    I can tell you I've build, serviced, refinished and modified close to 100 AR15's and short of two that who's barrels were shot out from 20k + rounds, I've never needed a special tool aside from basic armorers tools.

    If you don't have carbon on your bolt or bolt carrier, it's not an issue. If you do have a little, it's not an issue. ****, if you have a bunch, it's usually not a huge deal until you can feel it scraping.

    If you'd like me to take a look at your gun or go shooting with me sometime, please feel free to ask. I'm happy to help!
     
  12. twoclones

    twoclones Tri-Cities, WA Well-Known Member

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    What do you lube the CRAP out of your AR with?

    Today I lightly lubed mine with Hoppes oil. Later someone told me they use FP-10. A guy on YouTube uses axel grease!
     
  13. sprice37

    sprice37 Albany Oregon Active Member

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    Loose gas blocks was a smithand wesson problem. Hopefully the lube works
     
  14. coop44

    coop44 Tacoma ,WA Well-Known Member

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    Lube does not "fix" anything, get to the root of the problem.In the past 10 or so years I have seen guns and parts built hastily and with little skill. There a few simple things that a qualified smith will do. First is to test fire the gun (any gun) and carefully examine the brass, to the trained eye this will tell the condition of the chamber and if there are any headspace issues. Either will keep the gun from cycling properly. Sometimes problems can be linked to your ammunition, especially with cheap import ammo manufactured outside of SAAMI Specs. Second, on an ar type rifle check your gas tube alignment, a little bit off and it can combine with other issues to cause headaches, clean the gas tube (or just replace it, they are cheap enough) check with compressed air to make sure the port is clear, carbon can build up inthe gas port (especially from crappy ammo). Lastly, clean the buffer, buffer tube (lightly lube the inside of the tube), and spring, often overlooked by even the pickiest of AR owners, check it carefully for straightness and to be sure it is free of dents and dings (again this is a part that pretty cheap, if at all suspect change it).

    You may have to actually break down and have a vet show you to clean your locking lugs properly, my old D.I. would bubblegum himself if he saw yours.

    Of course switch to US made brass cased newly manufactured ammo and use a known to be good magazine(one that functions well in another ar)

    BTW I use milsurp CLP, bought a bunch years ago (almost out, anyone know where I can find a quart bottle?).

    My two cents
     
  15. Celtic Armory

    Celtic Armory Port Orchard, WA Member

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    Not having read all the other comments this is my take. It looks like the locking lug spaces in your feed ramps are very sharp. As you shoot they are likely shaving off a little material each time. To test for this you can load up some dummy rounds with clean polished brass and new bullets (no primer or powder). Load about 10 then cycle them through the rifle. Then look at the bullet and case to look for deep cuts and scratches. Chances are you'll have them. The cure is to take a needle diamond file and break the edges in the square cuts in your feed ramps.

    I would of course have to see the jam completely with the round in place to see exactly what it's doing and where it's binding.
     
  16. PDXGS

    PDXGS Aloha... yes, Aloha, Oregon Member

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    +1 on the feed ramps.
    Can you take a picture looking into the chamber from the bottom side of the receiver?
     
  17. twoclones

    twoclones Tri-Cities, WA Well-Known Member

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    I thought that's what I did :confused: The bottom would be to the right in these pics.
     
  18. bnr32gtr

    bnr32gtr Vancouver, WA Member

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    CLP, Mobil 1, RemOil, MilCom TW25B, whatever is plentiful, basically. 3 in 1 oil works great, too and you can get it pretty much anywhere. Don't spend your money on super fancy lube as it will burn off and need to be cleaned/replaced.

    Light lubing will only work for a little while. Douse the BCG, upper, etc. Do not be shy about it. Better to have too much than not enough. You can wipe off the excess if needed. Remember, these are tools to learn how to fight with.

    Those who want their guns to stay pretty and not get excess oil, dirt, carbon on them, should leave them in the safe.

    Several of us ran 900+ rounds at Dave's class with only basic cleaning(run a bore snake through the barrel, hose off the BCG with brake clean) and simply lubing the gun. We were running everything from Wolf, Tula, PMC, hand loads, S&B, Brown Bear, Golden Bear, etc. and the only times other than not enough lube that we had issues with, were someone's rushed reloads with primer pockets too lose and bullets not crimped. Those weren't the gun's fault though.

    Lube everything until it's dripping wet. I'll take some pics as I'm headed out shooting right now. Post when I get back this evening.
     
  19. Riot

    Riot Benton County, Washington Well-Known Member

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    This still doing that twoclones?

    Do you have a different AR lower you can try this on? If not, give me a ring and I'll let you use mine. The magazines might be sitting too low...when you showed it to me it was defiantly a feeding problem. The rounds were defiantly scrapping on the feed ramps.

    Everyone here can scream lube and clean...but these guns should function COMPLETELY DRY without a drop of CLP or oil on it.
     
  20. PDXGS

    PDXGS Aloha... yes, Aloha, Oregon Member

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    yeah...duh on my part....that's what I get for tracking five AR threads at once....sorry.
    I complete disagree on the need for that much lube as suggestedted by others. They shoudl run pretty well with just a film...or if you own a Next Generation Arms AR they can run completely dry....but that's another thread...