Bolt Carrier Group Discussion

Discussion in 'AR-15 Discussion' started by Shade, Sep 1, 2013.

  1. Shade

    Shade New Member

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    I have a Bushmaster AR-15, I have it in the A2 configuration, part
    sentimentality and part it fits me well like in that configuration, that or a few
    Gunny’s beat me into submission. Mostly, I shoot service rifle matches with
    it as well as some coyote control; and it is one of my SHTF rifles, should that
    need arise. I have been wearing out gas rings between 3,000 and 4,000
    rounds, and that seems more frequent than it should be. Any thoughts on
    that would be appreciated. I was thinking of an upgrade to a new bolt
    carrier group (BCG). Reliability and longevity are my key aspects that I
    want in a replacement/upgrade. Several that have come to the top of the
    list are:

    http://www.bravocompanyusa.com/BCM-...Auto-M16-p/bcm bolt carrier group auto mp.htm

    http://www.brownells.com/rifle-part...s-bolt-carrier-sku452000130-45574-102057.aspx

    http://www.aimsurplus.com/product.a.../M16+.223/5.56+Bolt+Carrier+Group&groupid=723

    I am not married to any of the options above, they are just what I have
    found researching the internet and those that had good reviews. Price is
    always a consideration, but it is not a primary. Reliability and longevity are
    primary. Price is flexible as long as the value is there.

    All ideas and comments are welcome.
     
  2. sweeper22

    sweeper22 New Member

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    1) I love BCM's BCG. They're a little spendy, but rock solid. A year ago they were easy enough to land for like $150. Most of my personal guns have them.

    2) You can also get a pretty great M16 BCG from PSA for $100-150. It's probably right near BCM quality, and this is where you're likely to get the most bang for your buck. PSA's stuff is constantly offered at blowout prices, it's just a matter of waiting a handful of days until a product/package that suits you gets listed on the cheap. Then pounce!

    3) The only premium finish BCGs I like are cerakoted M16s. These can be found for $160-230. In my experience they cycle smoothly and are easy to clean. My preference are those produced by STS Arms. I think NiB is probably perfectly great and all, but I dislike both the blingy look and the often squeaky cycling sound. Personal preference.

    There are others that are good. I also have a DD, which is fine. But the above three options are what I tend to count on and where I think you'll get the most value.
     
    Last edited: Sep 1, 2013

  3. sweeper22

    sweeper22 New Member

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    BUY THIS.

    Don't hesitate. Don't look back. You win.

    End of story.
     
  4. JonM

    JonM Moderator

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    bcm bcg are the best ones out there bar none.

    but i dont think the bcg is the issue. bushmasters are normally way over gassed and this leads to greater wear on the internals. only fix for that is a different barrel.
     
  5. Quentin

    Quentin New Member

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    I also like the standard BCM unit. Good price for a great BCG. Sweeper's link to the PSA BCG plus 5 PMAGs is amazing, too. As Jon said a new BCG probably won't extend ring life much. 3,000-4,000 isn't horrible for ring life considering how cheap they are. Let us know which way you go and how it works out!

    ETA:

    By A2, does that include the A2 rifle stock? If carbine, you might try an H buffer or even H2.
     
    Last edited: Sep 1, 2013
  6. Shade

    Shade New Member

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    Great information! Thanks.

    Had not hear this before. Is it that the port is drilled too large in the barrel?
    What size should it be?

    Full solid A2 stock, personal choice not to fond of the adjustable, and the
    A2 fits me well.

    But my younger son shoots a carbine AR, also a Bushmaster, tell me about
    the H and H2 buffers.
     
  7. Shade

    Shade New Member

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    My son and his carbine from today at the range. He had a friend sleep over
    last night they "camped out" in the deer camp trailer, and after breakfast we
    headed to the ISRA range in Bonfield, IL.
     

    Attached Files:

  8. JonM

    JonM Moderator

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    yup. depends on barrel length and ammunition that the barrel maker expects to be run through it or the end assembler requests.

    i believe colt uses .063 for a carbine length 16"

    makers like dpms, bushmaster, s&w market their guns and dont like to have returns so they tend to over size so they work with all civvy shelf ammo from 52grain to 75grain.

    only drawback as you have discovered is its a little hard on the gas rings and rear portion of the bolt and gas key. most of these types of guns never see a round count in the thousands.

    gas rings are cheap and 3000 is a typical count on overgassed guns to replace the rings. 3000 is also the typical point at which full auto m4 need to be changed. shorter gas tubes hotter gasses higher pressures more ring wear.

    being over gassed isnt really bad since it tends to be more reliable if the buffer weight is selected for it. thats why a lot of makers do it. just need to keep an eye on the rings
     
  9. Quentin

    Quentin New Member

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    Normally the H2 functions well with 16" and carbine gas, especially an overgassed BM or DPMS. But definitely hang on to the standard buffer which may be needed for weaker Tula. If you have to drop to an H (because of short stroking) you can swap a tungsten weight for a steel one in the H2 and standard and end up with two H buffers.

    There's a current thread going now with more info.
     
  10. Quentin

    Quentin New Member

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    Also a fresh action spring (or heavier aftermarket spring) might soften the cycling of the A2 a bit.
     
  11. KG7IL

    KG7IL Active Member

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    How about an adjustable gas block on the stock barrel?
     
  12. Shade

    Shade New Member

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    I was just looking into that as an option. Opinions/ideas?


    On a separate note:
    I think having a spare BCG on the shelf is a good idea, I also have
    several spare parts kits as I have multiple AR's.
     
  13. AgentTikki

    AgentTikki New Member

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    BCM $190 best service type

    PSA $150 Premium second best option

    An adjustible gas block will help with over gassing problems or try tuning your system with a heavier buffer (its cheaper and easier to do this) I would highly recommend buying one of the aforementioned BCGs just as a backup. A word of warning tho...these BCGs tend to get lonely and cold, so you might wanna wrap them up in a nice set of recievers...just to keep it safe........
     
    Last edited: Sep 6, 2013
  14. JonM

    JonM Moderator

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    that would work. but the issue with a lot of those is the gas port adjustors can move.

    your not liekly to wear out enough gas rings to offset the costs and hassle of finding one that works. just keep some on hand and check em using the stand the bcg on the bolt test after a cleaning.
     
  15. sweeper22

    sweeper22 New Member

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    Want a B+ grade BCG for a D- price? Here it is. PSA 8620 M16 $79.99.

    Is an 8620 bolt the top-flight standard? Nope. But it's generally good enough. It was the standard not so long ago, and will be equal to the challenge most shooters demand from their ARs. Good product, probably worth $150 when considering the 'real value' vs most other BCGs out there. Viable option for anyone looking for an affordable spare or attempting to upgrade a 'big box store' (DPMS, Bushmaster, S&W, etc) AR15.

    This is a solid BCG. I would not choose it for my go-to $1500 setup+, but it'd be fine in the previously mentioned roles (minor upgrade, spare, or driving a $700-900 build). It can be the ideal spare at about $87 delivered. I've used a couple of these for builds and have been pleased with the quality throughout.
     
  16. Shade

    Shade New Member

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    Thanks for all the input on this, I learned and that is good. I decided to
    purchase the BCM BCG. Did so a few minutes ago and a AR gunsmithing
    book with it by Dean Caputo.

    My next Brownell's order will have more gas rings on it.