I only saw one MP44 the whole time I participated. It made me feel all soft in the midle;) Awesome rifle, they are very rare and cost thousands. I have fired the MG42 and the MG39 not quite as expencive although still probably over $1000 for an operable. The price comes down quite a bit for a blank only gun. You can actualy buy a demillatarized MG for a couple hundred bucks but the action has been cut into three or four pieces with a torch. If you manage to get it welded back together you have to register it and get an automatic weapons license. The license is 2 or 3 hundred dollars and is renewed yearly. In order to get this license you sighn away your right to search and seasure. The BATF is allowed to enter your residence to inspect you weapons at any time. This aplies wether you buy the gun intact or rebuild it your self.
This is why I say the fun toys are expencive.
The bolt-action rifles fire blanks, crimped ends with no projectile. The autos have a few options. If you have a “blank gun” the barrel has been drilled through and filled with lead. These guns fire fine with crimped end blanks. They also do not require a automatic weapons license.
If you have an operational machine gun you have to adapt it to fire blanks. One method, used by the Germans for training was that the bullets were made of wood and an adapter was made that was similar to clamping a nail inside the barrel this was called a “bullet shredder”. This was used for the MG 39 and 42.
As for knowing if your hit, well that goes by the honor system or referees. Half the fun is dieing creatively, besides some times you get tired of running and it feels good to play dead for a while!