I have had them in .223, 5.45x39, & 7.62x39. I was lucky enough to get two of them with OEM thumbhole stocks. The 5.45 is good for 1 to 1.5" groups at 100yds. But that is bench rest with scope. I enjoy shooting them a lot and the 5.45 is still very "cheap" to shoot. It is a shame that the $10-$15 Bulgarian milsurp mags are gone! My 5.45 doesn't need a bullet guide and has been 100% reliable. I got lucky