Getting a preban lower and want to change the barrel of the upper I have now. I'm looking at the M4's in either 14.5" or 16". The problem I'm having is cmmg has at least a 5 week wait for the 14.5 but the 16 is in stock. Both are 1/7 chrome lined. And in the end the actual overal difference in length will only be ~1" after a2s. The only thing making me hesistant about teh 16" is that the bayo will rattle when attached. Anyone have a preferance? Could I possible get the 16" milled down at a later date by Kurt? Thanks.

If you're going to pop for a pre-ban lower, go with the 14.5" and a KKF flash hider.  Definitely my favorite configuration.  16" barrels look funny and won't take bayonets.

You'll thank me later.  [:D]

...or a 16" with mid length hand guards from Armalite.  I'm ordering one tomorrow (Monday) in a pre-ban confiruration.

Go take a look over in [url]http://www.ar15.com/forums/topic.html?b=2&f=27&t=140235[/url].  I'l go flat top upper with flat top Picatinny rail gas block and try one of those clamp on bayo lugs.

Don't forget, if it's 14.5" you have to [b]permanently[/b] attach the muzzle device to comply with the NFA short-barreled rifle rules, and I don't think the A2 hider is long enough.  Most guys go with the phantom or vortex or KKF extended hider, because they're longer than the A2 and bring barrel length above the 16" legal minimum.

And if you've never done it before, permanently attaching a muzzle device can be a pain.  If you go with the 14.5" barrel, see if you can get the vendor to attach it for you.  If you get the 16" barrel, you don't need to permanently attach the muzzle device.

Sorry if I'm telling you stuff you already know.

I'm currently running a 16" wilson with car front guards, which i'll keep. And pertaining to the 16" length of the 14.5 barrel, CMMG has a wide washer they use to get their 14.5s and a2s to 16". I've threaded and installed a brake on my ak before and had it spot welded. And I suppose just about any local machine shop should be able to mill a 16" barrel down to 14.5 and I could add the long a2 by Kurt at a later date... I just don't know if I can wait the 5 weeks. The biggest problem with waiting is I don't want to put more wear on my upper(only ~100 rnds through it now) then put a new barrel on. Just seems like that's asking for problems with mismatched worn parts.

One last question. The only 14.5 that CMMG has instock is the M4a3 upper with the Miculek brake installed. Does anyone have this and/or know how this brake is attached? I'm wondering if the break is removeable and replaceable with a long a2 or phantom...???