huklbrry Posted March 27, 2009 Share Posted March 27, 2009 Is it possible to put a M4 upper reciever on a standard AR15 to turn it into a carbine? If not, what would I need to turn it into a carbine?? Quote Link to comment Share on other sites More sharing options...
Hookster Posted March 27, 2009 Share Posted March 27, 2009 (edited) No Problem, just pop out the 2 pins and put on a new upper assembly pop the pins back in. Less than a minute, good to go. I have several uppers and a couple lowers and switch stuff up all the time. If you have a very old AR before they had the detent loaded pin in front you might need an offset pin up front Edited March 27, 2009 by Hookster Quote Link to comment Share on other sites More sharing options...
Duggan Posted March 27, 2009 Share Posted March 27, 2009 Yep, modular design means good to go. Quote Link to comment Share on other sites More sharing options...
huklbrry Posted March 27, 2009 Author Share Posted March 27, 2009 So all I need is an M4 upper reciever and barrel?? No other minor parts or anything else? Quote Link to comment Share on other sites More sharing options...
Hookster Posted March 27, 2009 Share Posted March 27, 2009 As long as you buy an assembled upper receiver that would be all you need. If it didn't come with its own bolt carrier and charging handle you can just use your existing ones. Do you have a particular brand/configuration in mind? Quote Link to comment Share on other sites More sharing options...
Mike Grasso Posted March 27, 2009 Share Posted March 27, 2009 You may run into headspacing problems, so your best bet is to buy a complete upper M4 receiver. Check the offsets on your front pin to see if A) you have mil spec pin, B) the new upper has mil spec pins. Just as Hookster stated, conversion pins are available in either direction. Mg Quote Link to comment Share on other sites More sharing options...
Hookster Posted March 27, 2009 Share Posted March 27, 2009 Hey Huklbrry, Here's a link with some good info http://forums.officer.com/showthread.php?t=81462 Quote Link to comment Share on other sites More sharing options...
huklbrry Posted March 28, 2009 Author Share Posted March 28, 2009 Thanks, you guys rule! Quote Link to comment Share on other sites More sharing options...
huklbrry Posted March 29, 2009 Author Share Posted March 29, 2009 I have an Armalite AR-15A4 with a 1/9 twist. I read somewhere that 1/9s aren't good for firing anything over 62gr. Would I be able to get an M4 complete upper with a 1/7 twist and have it still be compatible? Quote Link to comment Share on other sites More sharing options...
Mike Grasso Posted March 29, 2009 Share Posted March 29, 2009 I have an Armalite AR-15A4 with a 1/9 twist. I read somewhere that 1/9s aren't good for firing anything over 62gr. Would I be able to get an M4 complete upper with a 1/7 twist and have it still be compatible? 1 in 7 with the notched bbl is the standard M4 profile. It will handle a wider available range of ammunition the the 1 in 9. Mg Quote Link to comment Share on other sites More sharing options...
GTPSC Posted March 29, 2009 Share Posted March 29, 2009 You can't get something for nothin', huklbrry! As the twist rate gets faster (1-7 from 1-9, say), your probability for stabilizing the heavier bullets (with greater accuracy) goes up. The slower twists (usually) do a better job of stabilizing the lighter bullets (55 grain are the most common and cost less then the heavier bullets, again usually). Decide on what bullets you want to shoot and get the twist that will shoot the best. Is there such a thing as the best compromise? Probably, but you will have to do some testing to find out. There is no one best answer. GTPSC Quote Link to comment Share on other sites More sharing options...
huklbrry Posted March 29, 2009 Author Share Posted March 29, 2009 Any recommendations as to a good M4 upper that I can put on. Armalite's AR15A4 carbine uppers are made in a 1/9 as well Quote Link to comment Share on other sites More sharing options...
Hookster Posted March 29, 2009 Share Posted March 29, 2009 There are a lot of choices out there these days. Do you know if you want to go flat top or carry handle? railed front end or standard handguards? Do you want to run optics on it? My latest upper that I bought is a Smith and Wesson M&P 15T flat top with Troy Industries quad rail 1/9 barrel since I usually shoot 55gr PMC etc. I'm very happy with it. Quote Link to comment Share on other sites More sharing options...
huklbrry Posted March 29, 2009 Author Share Posted March 29, 2009 Yes, it will be a flat-top so I can run optics and also have a forgrip. Thanks for all your input guys! Quote Link to comment Share on other sites More sharing options...
huklbrry Posted March 29, 2009 Author Share Posted March 29, 2009 Also, what is the shortest M-4 barrel length a civilian can have? Quote Link to comment Share on other sites More sharing options...
spoolup Posted March 30, 2009 Share Posted March 30, 2009 The total barrel length for a rifle must be no shorter than 16". Some have done the 14.5 with a A2 birdcage flash surpressor (actually think its 14.7", or a modified longer birdcage) permanently attached to meet the 16" criteria. As for the twist. If you are sticking to 55gr FMJ, then either will be sufficient if you are going with the 75 gr taps or what not, then 1:7. Out of the 10.5 ARs I own, only 2 ar 1:7, the rest of the 223/5.56 are 1:9 with the exception of the 1:8 SS wylde chamber varmint rifle. Both my 308s and the 9mm are 1:10. The 22lr dedicated is 1:16. I have no issues with the 1:9 since I mainly shoot M193. Your results may vary. Quote Link to comment Share on other sites More sharing options...
Duggan Posted March 30, 2009 Share Posted March 30, 2009 (edited) Try for a LMT or Bravo Company m4 upper. There is absolutely no reason not to get 1/7 twist if you have the option. 1/7 stabilizes even 40 grain bullets just fine, and it eats 77 grain SMKs for breakfast. I think you're confused on your terminology ... an "m4 upper" means a 1/7 twist, m4 profile 14.5 inch chrome lined barrel with a T marked flat top receiver, almost always with m4 cuts nowadays. If it isn't this, it's not an m4 upper. My last AR was a LMT m4 upper. It was a great gun, I sold it to a friend so that he'd have a quality m4. Good luck finding any of them in this climate though ... LMT stuff is very hard to find now, because it's the best ... Edited March 31, 2009 by Duggan Quote Link to comment Share on other sites More sharing options...
huklbrry Posted March 30, 2009 Author Share Posted March 30, 2009 Thanks guys! Quote Link to comment Share on other sites More sharing options...
huklbrry Posted March 30, 2009 Author Share Posted March 30, 2009 Is the 14.5 legal for civilian purchase? I thought it was that the barrel length had to at least be 16". Quote Link to comment Share on other sites More sharing options...
spoolup Posted March 31, 2009 Share Posted March 31, 2009 Is the 14.5 legal for civilian purchase? I thought it was that the barrel length had to at least be 16". with a permanently attached 1.5" long flash suppressor it is legal. There are also some running a 11.5" barrel and a permanently attached 5.5" flash suppressor (bushmaster and DPMS made them from the factory that way)... don't really see the point in these, but to each their own. If I wanted a barrel that short I would get another AR pistol or SBR it and not worry about the added length of a decoration. Quote Link to comment Share on other sites More sharing options...
huklbrry Posted March 31, 2009 Author Share Posted March 31, 2009 Do you guys have any thoughts or experience on/with the LWRC M6 series? Im a firm believer in the adage "You get what you pay for", seeing how my benelli M4 performs compared to other shotguns I've fired, does the short stroke gas piston system on the LWRC M6 series rifles blow away current AR-15 technology? Quote Link to comment Share on other sites More sharing options...
Golden Dragon Posted April 1, 2009 Share Posted April 1, 2009 Do you guys have any thoughts or experience on/with the LWRC M6 series? Im a firm believer in the adage "You get what you pay for", seeing how my benelli M4 performs compared to other shotguns I've fired, does the short stroke gas piston system on the LWRC M6 series rifles blow away current AR-15 technology? I have seen some kits not run so well. My AR is good to go old style. Quote Link to comment Share on other sites More sharing options...
cksh8me Posted April 1, 2009 Share Posted April 1, 2009 www.jprifles.com and www.mstn.biz are the two top shelf uppers. The winningest upper in 3 gun tactical class is a 16" 1:8 twist MSTN. Big bucks giant quality. You couldn't go wrong with either. Quote Link to comment Share on other sites More sharing options...
huklbrry Posted April 1, 2009 Author Share Posted April 1, 2009 Thanks, I appreciate the info. Quote Link to comment Share on other sites More sharing options...
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