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Posted: 7/23/2009 10:08:59 AM EDT
| If the mil-spec tube dia is smaller than the commercial & pretty much the inside dia 's are the same ,for the buffer & spring . Wouldn't it be better to use the commercial size for a 308 build because of it s just larger& stronger. Not sure if it needs it & there doesn't seem to be a problem getting any of the favorite adj. stocks to go with the commercial tube , so what do ya all think . I have a CMMG lower I'm putting together & am going with a Magpul CTR or CRT or what ever it is . |
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Negative. On a commercial tube, the threads are cut into the tube, on milspec, the threads are raised. Since the tube inside diameter is the same, and the hole on the lower receiver is also a fixed size, all tubes have the same amount of metal at the critical point where they thread into the lower.
Ace makes a stronger tube if thats your worry: http://riflestocks.com/catalog/product_info.php?cPath=75_76&products_id=292 My $.02 is, for 308, get an AR-10 size tube from armalite and then run a RRA 9mm buffer in it. Works great, and not $$$. |
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Now ya got my curiosity a going . The threaded portion where the castle nut and where it is threaded into the receiver IS the strongest point of the tube . Its after that ,that makes me wonder and as I said ,it probably doesn't matter , it mostly will be strong enough any way.The collapsible stock is hanging on to that tube ,past that point .
As far as being raised or cut ,the threads should be the same with a well made piece. They are both cut (threaded by a die ),one way or the other . I 'm not being argumentative , I just am curious as to why there are two diff. tubes , did they make the mil-spec for weight control ,for the M-4? I have a commercial tube on the wife's carbine and now I will order a mil-spec and pull hers off to see the diff.. This new spec stuff ,I know nothing about . This stuff was not available thirty years ago when I first started building & repairing these AR type rifles . |
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Maybe I didnt use the best words.... Yes all threads are cut with a die.
What I mean is that on the commercial tube, the diameter at the threads is the same the diameter of the whole tube, (like we expect most any threaded bolt or such to be). On a milspec tube, the the threaded part is about the same diameter as a commercial tube [they both thread into the same lower], BUT the tube diameter is SMALLER than the threaded part, as such, the threads seem raised. The Why? question is another matter. I expect commercial style require less machine work. More pics: 
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| Man, I love photo's ,thanks & you even show the stock I want . .After seeing the photo's ,I will be getting a commercial tube ,more beef so to speak.I think its all about weight ,having a thinner tube takes off an ounce or two or would it be grams? Thanks for the info. |
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