having owned several 527 s i found the 2 main reasons for poor feeding are 1 the stock is not properly fitted to the action, which causes the trigger guard, mag housing not to mate perfectly into the grouve on the bottom of the action, giving the effect that the mag was to short, with the loading stroke of the bolt passing over the round instead of chambering it. 2 damaged mags this is easily done by simply dropping it or more often using to much force loading the last round causing the mag to spread which has the effect that the round usually sits nose up so when you attempt to chamber it the bolt again skips over it. both can be easily sorted.