I discovered this while training with my AR-15, but it would be applicable to any semi rifle with a bolt-hold-open feature. You'll have to forgive me if this is common knowledge, but I've never heard of anybody doing this and thought some of you might like to hear about it.
I just took the follower and spring out of a magzine. I still have the shape of the magazine to work around in a prone position, and can use the mag for immediate action drills, but now I don't have to use dummy rounds as a work-around for manipulating the bolt release. Taking a magazine apart beats the heck out of hunting down dummy rounds after they have rolled across a hardwood floor over and over again.
I just took the follower and spring out of a magzine. I still have the shape of the magazine to work around in a prone position, and can use the mag for immediate action drills, but now I don't have to use dummy rounds as a work-around for manipulating the bolt release. Taking a magazine apart beats the heck out of hunting down dummy rounds after they have rolled across a hardwood floor over and over again.