Before the larger models of these rifles were made, cost-cutting measures in production resulted in the removal of the internal bolt hold open, and relocation to the magazine follower. This change eliminated any possible speed up in the reloading procedure (due to the bolt closing upon removal of the magazine) but allowed the operator to more easily identify if the current magazine is empty. Some rifles were also equipped with a notched selector control which allowed you to lock the bolt rearward by closing the dust cover on the charging handle. In addition, the usual placement of the barrel through threading into the receiver was replaced by the cheaper method of pressing and pinning the barrel into the receiver. Rifles produced with these new features were known as models AP M70 B (fixed stock version), and M70 AB (folding stock version). As with the M70 series of automatic rifles, these models failed to be produced in larger quantities before further cost-efficiency production measures gave way to yet another model.