Some AK mags, some M-1 carbine mags, and all the mags designed for the Rem 742/7400s engage the bolt with the back of the follower.
Thanks for that. I know I've heard Ian and other Youtuber experts on firearms history frequently mentioning a gun's failure to lock open on an empty mag, whether it's a wear/breakage issue, or a design decision by the manufacturer. It's really quite common to have this feature, where the lower edge of the bolt or bolt carrier or some appendage grabs the back of the follower after the last shot and stays open. Some firearms will then drop the bolt on pulling the empty mag - a secondary feature built separately from the BHO - or stay open due to a secondary feature which takes advantage of the follower being used for BHO to set into place, the bolt then being cycled a bit further back, or a bolt release being pressed, to release and chamber the first round from a newly inserted mag. It's not a rimfire thing, it's design decision on any number of calibres.


















































