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Thread: Yankee Hill Bolts and BCGs - Questions

  1. #51
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    Whytep38,

    This thread has gone away from your original question. I don't know after some looking what standards YHM holds their BCGs to. I will say this if you are looking for a bolt carrier group Yankee Hill sells them on their website for $123. It is not a full auto carrier and gives no description of metal or QC used:

    http://yankeehillmachine.com/store/product542.html

    If you are willing to spend only $17 more you can get this:

    http://www.bravocompanyusa.com/BCM-B...0auto%20mp.htm

    BCM® (MPI) complete bolt carrier group is fully assembled. Bolt carrier group (auto version) for your AR15, M16, or M4. Parkerized exterior and chrome lined inside carrier. Machined to USGI specifications. This M16/M4 carrier includes the proper Mil-Spec gas key. Gas key is chrome lined and heat treated per GI specifications. Gas key is secured to carrier via USGI domestic mfg Grade 8 fasteners and properly staked per Mil-Specs. These properly hardened parts insure a strong staking and proper gas system functioning. The bolt assembly is machined from the correct Mil-Spec Carpenter No. 158® steel, shot peened for increased strength, includes tool steel machined extractor and ejector, BCM Extractor Spring, and is HPT (High Pressure Tested) and MPI (Magnetic Particle Inspected).

    Features Milspec Carpenter No. 158® steel HPT Bolt (High Pressure Tested/ Proof) MPI Bolt (Magnetic Particle Inspected) Shot Peened Bolt Chrome Lined Carrier (AUTO) Chrome Lined Gas Key Gas Key Hardened to USGI Specifications Grade 8 Hardened Fasteners Key Staked Per Mil-Spec Tool Steel Extractor BCM Extractor Spring Black Extractor Insert Mil-Spec Crane O-Ring

    It says something to me that a company would say this up front. Not dissing on Yankee Hill but there is absolutely no description of what their BCG has had done to it. That extra $17 is nice for piece of mind. I realize this doesn't answer your question but the lack of information might be a clue. Good luck man.

    -Jax
    Last edited by jaxman7; 11-17-10 at 16:39.


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  2. #52
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    Quote Originally Posted by jaxman7 View Post
    Whytep38,

    This thread has gone away from your original question. I don't know after some looking what standards YHM holds their BCGs to. I will say this if you are looking for a bolt carrier group Yankee Hill sells them on their website for $123. It is not a full auto carrier and gives no description of metal or QC used:

    http://yankeehillmachine.com/store/product542.html

    If you are willing to spend only $17 more you can get this:

    http://www.bravocompanyusa.com/BCM-B...0auto%20mp.htm

    BCM® (MPI) complete bolt carrier group is fully assembled. Bolt carrier group (auto version) for your AR15, M16, or M4. Parkerized exterior and chrome lined inside carrier. Machined to USGI specifications. This M16/M4 carrier includes the proper Mil-Spec gas key. Gas key is chrome lined and heat treated per GI specifications. Gas key is secured to carrier via USGI domestic mfg Grade 8 fasteners and properly staked per Mil-Specs. These properly hardened parts insure a strong staking and proper gas system functioning. The bolt assembly is machined from the correct Mil-Spec Carpenter No. 158® steel, shot peened for increased strength, includes tool steel machined extractor and ejector, BCM Extractor Spring, and is HPT (High Pressure Tested) and MPI (Magnetic Particle Inspected).

    Features Milspec Carpenter No. 158® steel HPT Bolt (High Pressure Tested/ Proof) MPI Bolt (Magnetic Particle Inspected) Shot Peened Bolt Chrome Lined Carrier (AUTO) Chrome Lined Gas Key Gas Key Hardened to USGI Specifications Grade 8 Hardened Fasteners Key Staked Per Mil-Spec Tool Steel Extractor BCM Extractor Spring Black Extractor Insert Mil-Spec Crane O-Ring

    It says something to me that a company would say this up front. Not dissing on Yankee Hill but there is absolutely no description of what their BCG has had done to it. That extra $17 is nice for piece of mind. I realize this doesn't answer your question but the lack of information might be a clue. Good luck man.

    -Jax
    You nailed it like I said these companies are here to give you what you may want and do the best by you and your money. THAT THEY CARE ALONE should make a differance BUT does not mean the others parts are bad and even different at all. For all we know YHM is tested IDK. What I do know is we have to start understanding this AR market for what it is, and not discredit all these other non tacticool companies because there not a certain name.

    I am sorry to do this post but I get sick of all this shit information, lies, distrust and lack of knowledge in the AR industy
    Last edited by DSZM4; 11-17-10 at 16:49.

  3. #53
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    Quote Originally Posted by DSZM4 View Post
    I don't think its fair to state companies by name for the same reason I don't think its fair to discredit companies that buy the same parts ether.



    YES IT IS IRRELEVANT who cares where its from if you want a tested bolt buy it, if its made right. If non tested is okay then, YHM is okay if its made right and I bet it is since its coming from the same place as other companies source from.

    OMG is the point across yet??????

    Are we done with this little lesson in how a large part of the AR world is?

    Since you are aren't naming names, let's put some of this in context.

    Colt (for instance), buys parts from other companies (as they no longer make everything in house). When they get the parts their ordered, they go into a inspection area. Colt does their own QC before allowing the part(s) to make it out onto the assembly floor. If the part does not meet their standards, the part goes back to the manufacturer.

    Another company also buys parts from the same company as Colt. Just one problem though, they do not QC the parts they get and in SOME instances, gets the Colt rejected parts.

    So are the parts you get from one company the same quality as you get from another? No (as one does QC and the other one does not).

    YHM buys BCG's from CMT. Great. They don't do HPT or MPI on them. So that means that they don't catch about 3%-5% of the failures that HPT and MPI discovers. The company that does HPT/MPI also (Typically) has jigs setup so that they can quickly QC the dimensions on each and every BCG. So you, the consumer are much less likely to receive a bad one.


    C4

  4. #54
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    Quote Originally Posted by C4IGrant View Post
    Since you are aren't naming names, let's put some of this in context.

    Colt (for instance), buys parts from other companies (as they no longer make everything in house). When they get the parts their ordered, they go into a inspection area. Colt does their own QC before allowing the part(s) to make it out onto the assembly floor. If the part does not meet their standards, the part goes back to the manufacturer.

    Another company also buys parts from the same company as Colt. Just one problem though, they do not QC the parts they get and in SOME instances, gets the Colt rejected parts.

    So are the parts you get from one company the same quality as you get from another? No (as one does QC and the other one does not).

    YHM buys BCG's from CMT. Great. They don't do HPT or MPI on them. So that means that they don't catch about 3%-5% of the failures that HPT and MPI discovers. The company that does HPT/MPI also (Typically) has jigs setup so that they can quickly QC the dimensions on each and every BCG. So you, the consumer are much less likely to receive a bad one.


    C4
    You are correct if you are a person that beleives in or seeks out that type of QC or if you beleive proof testing does not cause its own failures down the road, and you are willing to trust the QC is done correctly, then YES you would be correct.

    This is why I don't trust any gun or parts till I have seen it perform, over a long peroid of time. I have seen HPT fail sooner than non HPT and I have seen the opposite. I have also seen 8620 bolts fail inside of 1000 rounds.

  5. #55
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    Quote Originally Posted by DSZM4 View Post
    You are correct if you are a person that beleives in or seeks out that type of QC or if you beleive proof testing does not cause its own failures down the road, and you are willing to trust the QC is done correctly, then YES you would be correct.
    Good god, man, do you even listen to yourself?

    "Airbags save lives if and only if you are one of those people who believes airbags saves lives and don't KILL YOU FASTER INSTEAD!"

    Sorry, I'll be one of those blind sheeple that accepts without conducting my own industry-grade tests that:
    My airbag will help protect me in a crash
    and
    Quality control measures don't break things more.

    Did you need a trip into outer space to accept that the Earth isn't flat, too? Or was your 3rd grade science textbook filled with marketing lies, too?

  6. #56
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    Your right accept one thing I truly beleive proof rounds can weaken the part because the part is not all that well designed for a proof round to be fired in the first place especially if proof testing is not a spec used with consitancy.

    I agree with testing and don't need to see it with my own two eyes to trust testing. I JUST DON'T TRUST proof testing a standard designed AR bolt. I have seen proof testing certs from different companies enough to not want to chance it blindly. Stress fractures start small too small to see or even test for sometimes. I don't drink this cool aid on a AR bolt other designs sure not a AR.

    I also think NP3 is a better surface than shot peened, just a opinion it doesn't matter ether.

    STILL IT DON"T MATTER its a opinion and there a holes every bodies got one.

  7. #57
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    Quote Originally Posted by DSZM4 View Post
    I have seen proof testing certs from different companies enough to not want to chance it blindly. Stress fractures start small too small to see or even test for sometimes. I don't drink this cool aid on a AR bolt other designs sure not a AR.
    Care to explain?

  8. #58
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    YHM buys from Stag = we call this a clue.

    OP - YHM BCGs are not milspec.

    Shell out the extra Jackson for a BCM BCG.
    We miss you, AC.
    We miss you, ToddG.

  9. #59
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    Quote Originally Posted by .45fmjoe View Post
    I'm going out on a limb and I'm going to say he is talking about BCM since I posted one of Paul's manufacturers is, or at least was, CMT. I say this because one of my BCM bolts is marked CM and MPT. I also know my BCM bolt was made to the TDP and who made it is irrelevant as long as it was made to the TDP.
    BCM does not buy bolt's from CMT.


    C4

  10. #60
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    The phrase "full of crap" is entering my mind right now. Seriously, stop posting in this thread. That's not a request.

    Quote Originally Posted by DSZM4 View Post
    You are correct if you are a person that beleives in or seeks out that type of QC or if you beleive proof testing does not cause its own failures down the road, and you are willing to trust the QC is done correctly, then YES you would be correct.

    This is why I don't trust any gun or parts till I have seen it perform, over a long peroid of time. I have seen HPT fail sooner than non HPT and I have seen the opposite. I have also seen 8620 bolts fail inside of 1000 rounds.



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