I have two Axis rifles with Boyd stocks...a .223 and a .308 HB. I put Boyd's thumbhole stocks on each of them and had the same issue with the mag not dropping when the release was pressed. Very difficult to remove the mags. As mentioned by DaveB, the mags need to "hinge down" at the front to release. On both of these stocks, I cured my problem completely by carefully removing material from the back of the magazine hole in the stock. As received, that was a vertical surface and it needs to have about a 1/16 inch removed from the bottom edge...tapering toward the top. When released, the mag needs to be able to pivot down a fraction. The pivot point being the back latching projection on the mag. If it can't pivot just a tiny bit, it won't drop. Both of mine now behave normally. My own procedure was to file/rasp a bit, then try it. When it dropped freely, I stopped. It didn't take much. No mods to the mags were made.