The problem that I have found with all commercial M14 (M1A) stocks is that all that I have ever seen with the exception of the Chinese stocks are not cut correctly for the semiauto Chinese M14 receivers.
Chinese semiauto M14 receivers run the right rail lower cut, (the cut with the angle machined into it) all the way to the rear of the right rail, while all other commercial semiauto M14 type receivers have the right rail machined like M1 Garand rail and end the lower angled cut at the rear of the right receiver leg.
I have found that I must modify any commercial semiauto M14 stock to correctly fit Chinese M14 receivers, this is not a major modification, but I find that it is required to correctly seat the receiver in the stock and prevent canting of the receiver, and issues with front band tension and the gas cylinder touching the side of the stock channel.
Please keep in mind that I am down here in the lower 48 and do not have access to the latest Chinese M14 receivers, and I am assuming that they have not changed their manufacturing methods on their newer receivers.