The case head of the 2nd one from the left says 45 long colt, but the inside diameter is .309?? Case length is 1.275. Primer pocket is .172. Case head diameter is .355-.356. could someone have fromed a 30 carbine from a 45 Long Colt???
was refering to the bigger case. The spotter round in much shorter than the Browning M2 case, and has more taper. Also the bullets are differernt in weight and make up. The trajectory is identical to a 106mm round.
Just a wild guess anyway