[Mariner]

"It’s a Browning .30cal NOT A .50 cal !!!!!!"

Are you sure?

I think I see lips on those rounds which leads me to believe it's Russian 7.62 x 54.

[calex59]

It is a Browning M1919, fired one enough to know one. The rounds don’t have rims on them,IMO, they are rimless. I wouldn’t doubt that during WWII the russians had some M1919s under the stupid lend lease program FDR started, but those look like 30-06 rounds to me.