Works fine for me - Mitchell Defense Enhanced A5 Length Buffer Tube

An A5 buffer tube with enhanced extension on the receiver side which does three things: allows for extended castle nut install (e.g. FCD CN5F, HK416 A5 nut, SOLGW A5 nut, etc.), provides physical support of the rear of BCG for anti-tilt during carrier cycling, and locks the buffer tube detent alignment into place making installing and removing buffer tube from lower receiver a little more straight forward (i.e. easier). Can also back the castle nut completely off the threads (towards the back of the tube) and then rethread easily, giving you extra room during install of the take-down pivot pin spring and detent, which go under the end plate before tightening the castle nut.

Another reviewer said it is not hard anodized with the finish rubbing off, but mine does not have this problem. I purchased mine before the price jump, in early 2026.

Makers of A5 buffer tubes with enhanced extensions only include Mitchell Defense, PWS and V Seven. All other options for A5 buffer tubes do not have the enhanced extension over the detent but they also work fine without it (e.g. Kratos, BCM, KAK, FCD, ADM, BKF, SOLGW, FM, etc.).

I do very much prefer buffer tubes with numerous drain holes for water, which this has. But that also means there is no air compression inside the buffer tube during cycling so the gas system must be properly "tuned" to prevent hard cycling. That is not usually a problem because stiffer buffer springs and heavier buffer weights will almost always resolve that, and if that's not enough you can add an adjustable gas block up front.

Only cons for me is that the price has jumped a little too high and it does not come in colors like Kratos or ADM A5 buffer tubes. :( But alas, black is the standard color for AR-15's...