Skip to main content
Help Center Community Shop

AR 15 questions

Blckhrn
I'm looking into buying a preban AR 15 here on GB with the idea of possibly getting an ALS .50 BMG conversion later.

What is meant by small pin/large pin? Can this affect my plans for the conversion?

As for the conversion, I'd like to go with the match chamber but could be shooting surplus ammo as well as match. Can I get away with this?

"You can build a man a fire and keep him warm for a couple hours or douse him with fuel oil and keep him warm the rest of his life"
0

Comments

10 comments

Date Votes
  • vallopez2000
    You should really ask this question over on the ar15.com forum. There is a wealth of weapon specific info over there.
    0
  • Boomerang
    quote:I'm looking into buying a preban AR 15 here on GB with the idea of possibly getting an ALS .50 BMG conversion later.After September of last year there is no such critter as preban anymore.quote:What is meant by small pin/large pin?This refers to the front pivot pin. Colt used to put large pivot pins in their receivers for some reason.quote:Can this affect my plans for the conversion?No.quote:As for the conversion, I'd like to go with the match chamber but could be shooting surplus ammo as well as match. Can I get away with this?I can not answer that one.

    Boomer

    "Success is to be measured not so much by the position that one has reached in life as it is by the obstacles which one has overcome while trying to succeed"

    . and the antithesis to this philosophy was uttered by Bill Clinton "I smoked it, but I didn't inhale."[V]

    NRA Life Member
    0
  • artvls
    Go to www.biggerhammer.net to get detailed info on the big hole small hole types. Small hole is what is used on M-16's, large hole was to prevent the use of M-16 upper on semi autos.
    0
  • Blckhrn
    "After September of last year there is no such critter as preban anymore."

    Well, there was a pan and guns made before that are pre ban. Also, some early AR 15's were made w/out the sear block, which, I would imagine, still lives after the ban.

    "You can build a man a fire and keep him warm for a couple hours or douse him with fuel oil and keep him warm the rest of his life"
    0
  • nmyers
    You're right; even though the ban is over, there are still rifles that can be called "pre-ban". Just don't pay a premium for one.

    I'm not sure what you are saying about the sear block, but that should have nothing to do with your choice of rifles unless you already possess a registered auto-sear.

    There are bushings that allow the mating of uppers/lowers with different pin sizes. However, the conversion unit you are considering should only be installed on a small pin lower. While I haven't fired such a conversion, I would not be quick to spend > $1,600 just to find out that such a combination produces more punishment than the human body can endure. But, it's your money.

    Neal
    0
  • Boomerang
    quote:Originally posted by Blckhrn
    "After September of last year there is no such critter as preban anymore."

    Well, there was a pan and guns made before that are pre ban. Also, some early AR 15's were made w/out the sear block, which, I would imagine, still lives after the ban.

    "You can build a man a fire and keep him warm for a couple hours or douse him with fuel oil and keep him warm the rest of his life"
    I have Bushmasters without sear blocks, and they were made even when there was ban. Now there is no ban. That is all I was saying. Colt did the PC large pivot hole and sear block thingy. I have sold all my Colt ARs except for one, a CR624. Bushmaster and ArmaLite are my preferred ARs now.

    Boomer

    "Success is to be measured not so much by the position that one has reached in life as it is by the obstacles which one has overcome while trying to succeed"

    . and the antithesis to this philosophy was uttered by Bill Clinton "I smoked it, but I didn't inhale."[V]

    NRA Life Member
    0
  • drobs
    I would not use a Preban Colt for your 50 cal conversion. The Pre Ban Colts will always hold their blue book value. No sense in beating the hell out of an old gun when new complete lower receivers are readily available for $200 or less.

    Check out complete lowers at www.rguns.net

    I just just bought a complete collapsible 4 position stock DPMS lower from them for $216 OTD.

    Specifically: http://www.rguns.net/009_31.html

    Regards,
    gadsden.jpg
    0
  • Python
    Blckhrn;
    There are rifles out there being touted as pre-ban that are in fact ban period manufacture. Original colt pre-bans are far to valuble to beat up with a .50 cal upper. I have never been a fan of this particular conversion. Small pin recievers are A1's and early A2's. The reciever pin diameter was incresed to provide stronger, more stable lock/link with the lower. It is, in my opinion, asking way too much of the AR lower to handle the monsterous pounding of the .50BMG round. Rifles chambered for this round are big and heavy for a good reason. The chamber pressures and recoil of this round demand a lot of good steel around it. If something goes bad in the rifle firing it, it will get real ugly real fast. I own a Maadi-Griffin M-91, a Barret M82A1, and Serbu BFG 50, all are .50 BMG. The lightest of the three tips the scales at 23 pounds. If you want a AR, great. But to convert it to fire the .50 BMG, even as a single shot, is asking a lot of the aluminum lower. I must confess this is only my opinion. I have no definitive proof this conversion is a bad idea. But the numbers seem a bit lop sided, when you compare the round it was designed to fire and the big Browning machinegun round. I can say for certain, I don't want to be behind the upper should it shear the pin holding it to the lower. Not with that much power pushing it rearward.
    Again just my two cents.

    Kill all the lawyers and the world will be much better for it.
    0
  • Blckhrn
    Well, thanks to everyone who posted. I'm going with an Anzio 50, kinda doubted the 50 BMG conversion thing all along. I'll pick up some sort of AR 15 later. I guess the bill is in Congress now regarding making transfer of the 50 BMG illegal, with a grandfather clause. They're saying that the round has only one purpose, to kill. I'd like to know how many of these are in law abiding hands now. I have never heard of anyone being shot with one other than in wartime.

    When my FFL transfers a gun to me he has to do a law enforcement check. The real concern is that terrorists can acquire these. If they can, then law enforcement has dropped the ball. Once again, our gov't is infringing on our rights as a result of their own incompetence.

    "You can build a man a fire and keep him warm for a couple hours or douse him with fuel oil and keep him warm the rest of his life"
    0
  • vicg1
    preban still has significance as many states enacted their own versions of the AWB that have not expired and gun owners in those states need preban rifles if they want the evil features... they still command a slight premium because of this.

    vipersig.jpg
    0

Please sign in to leave a comment.

Recent Activity