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Posted: 2/23/2004 6:39:33 AM EDT
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what's the deal with this anyhow? i'm looking into getting a 6 position for my BM, but i keep hearing that anything non-colt is not mil spec... it doesn't really matter to me, i'm just wondering what the difference is. is it just the # of positions, or something else? |
| i was 1/2 thinking about the VLTOR but i don't know if i can justify the lootcakes for one. that's how i noticed actually though. they say the VLTOR only works with mil-spec tubes. so i'm assuming then that the bushmaster/rr/oly/etc tubes are thinner material. correct me if i'm wrong, but the buffer and spring are the same diameters on colts or any others, meaning the ID of the buffer tube has to be the same. |
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M4-guy: ain't nobody going to bother you about it unles you are doing something stupid. but if you plan on doing something stupid, just set it to the length you want and pin that fuc*er. i'm seeing them for between 165 and 175 complete (stock/buffer tube/buffer/spring). i don't know if i want it that much more than a $75 bushmaster 6-pos. oddly enough i'm having just as difficult a time NOT buying it, or a magpul for that matter. [:D] this stuff really is like crack. |
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Outer tube diameter is the difference. Inner diameter is relatively consistant. Enough so that all manufactures springs and buffers work within all brands unless specified by the manfactured design. There are some custom tubes that require a special spring and buffer. Rare though. JohnM back from Iraq |
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Quoted: Would someone with a Colt buffer tube give me a caliper measurement of the O.D.? That would allow me to measure my tube to see if it is "Milspec" or not. I'm a Vltor owner. The colt and Vltor tubes measure in at 1.150. The aftermarket tubes (at least the tubes I checked [i]rra, bushmaster[/i]) measure in at 1.065 to 1.170 inches. I rounded off to the closes .005 ls |
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L.S. is correct. The real difference is in the threads. In what appears to be an ease of manufacturing move, the non spec tubes have the threads as the same O.D. as the tube roughly. Makes machining easier I think?? the spec tubes however have it so that the threads are considerably higher than the O.D. of the tube. why this couldn't have been done on the larger none spec tube I dont know. On ethe CNC is programmed then away you go. there is no real viable reason to have the difference (Opps - forgot about protecting the Colt TM name!! maybe thats why) the end result is you have threads on the spec tube that engage the FULL thread on the receiver where you have about half or a little more on the none spec tube (you can really notice it when you compare both side by each). the end result is this. If you are gonna use the gun as a prybar or step to lift a heavy dude over a fence then the full thread engagement is nice. otherwise it doesnt really matter. Mark |
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The real difference is in the locking lug that runs 3/4 the length of the bottom of the tube, the BM/RRA has 3/32-1/4in radiused edges and the Colt/vltor tube has almost square edges. This means that if you attempt to put a colt/vltor stock on a RRA tube you will fail misserably, or destroy the stock. It's like trying to put a larger square peg into a smaller round hole [b]JUST NOT GOING TO HAPPEN[/b] You can put RRA stocks on Colt tubes, but they will rattle, YOU CANNOT put a Colt stock on a RRA tube. |
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Quoted: The real difference is in the locking lug that runs 3/4 the length of the bottom of the tube, the BM/RRA has 3/32-1/4in radiused edges and the Colt/vltor tube has almost square edges. This means that if you attempt to put a colt/vltor stock on a RRA tube you will fail misserably, or destroy the stock. It's like trying to put a larger square peg into a smaller round hole [b]JUST NOT GOING TO HAPPEN[/b] You can put RRA stocks on Colt tubes, but they will rattle, YOU CANNOT put a Colt stock on a RRA tube. Finally a correct reply among a plethora of assumptions and misinformation. Green0 is correct. |
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Okay... The specs for the rifle call for the tube to be 1.150 in diameter and the threads to be 1.1875 -- This requires that the tube undergo quite a bit of machine shaping. Many years ago, when the AR clones first started, one enterprising man decided that the cost of these tubes was WAY too high and he needed a way to make them for less... So, by starting with a 1.170 tube, the threads could be cut into the tube and no exterior shaping was needed -- stocks would be made to fit the new larger tube, or older stocks could be made to fit the larger tube (easier to remove material than add it). The down side is, the thread diameter is not up to specs and the tube is cut for probably less than 50% engagement (never figured it out really)... green0 and TT, feel free to pull the techdata package and take a look if you have any doubts. |
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