Letter Re: Advice on 5.7 x 28 Uppers for AR-15s

Mr. Rawles:
I would be interested in your comments on the AR-57 conversion for AR-15s and its potential use after SHTF. – Mike K.

JWR Replies: Mostly for purposes of experimentation, I bought both rifle and pistol AR uppers in the 5.7×28 caliber. (I own just one “Pistol ” marked AR lower, sans buttstock), and also have a 10″  5.56 barrel for it.) En toto, I have put nearly a thousand rounds through my two 5.7 uppers. I found that the pistol upper in 5.7 functions well, but the rifle upper in 5.7 jams frequently for some reason that has been difficult to trace. These jams smash the cartridges, and are slow to clear, since they necessitate removing the magazine. That was disappointing.

The top-mounted magazine allows very low prone shooting, but I found that it was almost a three-handed operation to swap magazines. I can’t imagine ever having it be as quick and convenient as traditional magazine swaps. That would take a lot of practice.

Most importantly, since it is still essentially and oddball caliber and under-powered, I consider the 5.7×28 cartridge a substantial STEP DOWN from the 5.56 mm NATO in power and range. So I plan to continue to use my 5.7 uppers as transitional trainers for my younger children, and perhaps some varmint shooting, but nothing more.

In essence, the AR-57 has good looks, but it simply doesn’t have a lot else going for it, at least in the context of disaster preparedness. My recommendation is to skip it unless you plan to carry an FN Five-Seven as your primary sidearm. Again, since it is an unusual chambering, that approach would necessitate laying in a lifetime supply of ammunition. Buying guns in oddball calibers goes against the conventional wisdom of common standardized calibers for survivalists.