I didn't hear a "bang" but the primer was hit and the bullet lodged in the bore just ahead of the chamber. Obviously there was powder, some powder. I haven't searched the empties yet to ascertain any anomaly. There should be some tell-tale evidence on the fired case. Powder charge was 21 grs 2400. For small lots like this I'm usually very careful about powder and visually check after charging the case.
And to illustrate how absent minded I can be.... These 7.7x58mm were loaded to touch the rifling. Notice the ones on the right are much longer. Too long for the magazine but I didn't notice until I was at the range trying to load them into the magazine. They fired fine but I had to single load them. 314299. Duhhhh!