look close at :16 sec mark she reaches with her left hand above the receiver then look at her left hand under the stock her pinky and ring finger are curled as if holding the cartridge, compare it to her grip on the 1st 6 shots. on shot seven there is no recoil.....she flinches theres no bang no puff from the muzzle. She pulls the trigger flinches....then things go wrong.
Wow you are observant.....that is exactly what happened.....she can be seen pulling the trigger with no significant recoil......pulls bolt to rear and clearly pulls out a carteridge with left hand and drops it to the ground (you can see it)......the rides the bolt forward and the the failure. I thind that carteridge she dropped was an empty one......there was a projo stuck in the barrel!
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Like I said I'm no expert.....but then after re-watching after reading mac1911's video......I think there was squib in the barrel.Garands were tested with proof charges until they blew up: Springfield Armory routinely tested overcharges to minimize the danger to soldiers. They were way over double the chamber pressure and usually blew out the bottom. This was different.