Re: SBR schooling
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 6.81star</div><div class="ubbcode-body">I currently have an 18 in armalite with a mid-length gas system. I have been eyeing sbr's and thinking about sending in for my stamp. But I have a few questions will the mid-length gas system cycle w/o problems if I shorten the barrel to 14.5. Also my barrel is chrome lined can I shorten it and recrown it w/o damaging the chrome lining or should I just buy a 14.5 upper. I want to run the ergo 93 stock with a 13 in rail and noveske pig so if you have any similar pics throw them up thanks. </div></div>
6.81star,
I you cut down your 18" barrel, the gas port may or may not be of the correct diameter to run reliably at 14.5". Many shooters are reporting good reliability with the BCM 14.5" middies, so I don't think there is an issue with that barrel length and gas-tube length combination. I assume we are talking 5.56x45mm / .223 (?).
I agree with the other posters that going through the hassles of SBR paperwork for a 14.5" barrel is of limited return on investment. I have a Noveske 14.5" with pinned/welded flash hider and like the length for carbine use without having to register a lower. If I were doing it again today I would probably buy one of the BCM EAG uppers with a pinned/welded BattleComp, as my Noveske has the carbine-length gas system.
I first saw the Noveske KX3 "flaming pig" demo'd at an EAG carbine class back in early 2006. Pat had one on a 10.5" Noveske upper, and the peripheral blast was definitely greatly reduced compared to similar-length barrels. Perhaps a greater benefit is that John's version of the Krinkov device is that it appears to add back pressure and make the shorter barreled-uppers more reliable with a greater variety of ammo. There is no free lunch, however, as it does add significant weight and length. The flash suppression is not as good as many, especially when it gets dirty, and it's not particularly easy to clean. I personally believe that the usefulness of the KX3 is dubious for barrels over 12.5", as the peripheral blast of a 14.5" barrel (5.56x45mm) is not bad, and instead of adding such a long/heavy chunk on the end I'd prefer just to use a longer barrel with conventional flash hider.
If I thought I needed an under-the-trench-coat VSBR (8"ish), I think the KX3 would be a definite advantage as it was with the original Krinkov muzzle brake.
If I really needed an SBR for easier ingress/egress from vehicles, I believe that I would personally go with an 11.5" (carbine-length) upper <span style="font-style: italic">a la</span> Colt Commando or BCM. Check out the BCM subforum on ARFcom for a sticky on why Paul chose the 11.5" versus the 10.3"/10.5".
ETA: The Levang Linear Compensator reportedly has many of the positive attributes of the KX3 without some of the negatives. I have no personal experience with it, but folks I trust have recommended it as an alternative.