more reliable than a 10/22, marlin 60. The cmmg fiberglass mags work very well for me. many thousands of rounds, dont recall any feed jams, occasional short stroke or weak ejection, always a ammo issue. the feedlips on the cmmg mags are showing some wear though, and i think they will be useless before hitting 5000 rounds each. The black dog mags work ok. maybe one feed failure in a few hundred, maybe if i can get some more rounds through them, might start smoothing out. the old cmmg kits would not eject live rounds, due to the extractor not making contact with the case in battery, requiring the case to push itself into the extracter. duds were a issue.
That wont be an issue unless buying used thou. My kit had a weld fail early on, and cmmg replaced it, and payed shipping. replacement is the one i speak about. Mine can hit a soda can at 30 yards easy enough. 16" chrome lined 1 in 9. if your concerned about accuracy. And the bolt hold open adapter may require work to fit the blackdog mags. I gave up on the bolt hold followers, but do use the manual bolt lock.