[quote=“Ray Meketa”]Hey Falcon, errrr, I mean Rick,
Well that’s embarrasing! That was probably on the Gunners Mate tests. I’m sure i got the answer right. I just couldn’t remember it. :) :)
Still, I understand the blowback principal. But I find it hard to believe that the case would be extracted while the pressure was still high enough to expand the shoulder and neck without rupturing the head. The whole concept of blowback is that the primer ignites the charge while the bolt or breech is still travelling forward and the pressure is low enough before the mechanism can recover from the forward momentum and start back.
But, I’m probably wrong. Again
The one important thing that the link to the explaination of the operation of this gun missed out is that the chamber is much longer than the cartridge case. If you slip a loose cartridge into the chamber is disappears out of sight. The rebated rim allows the bolthead to follow the cartridge into the chamber. This was discussed in some detail in an earlier thread, I likened the case to a greased piston.