Correction - Not in Pete’s auction
This is an experimental T5 50/30 which is basically an elongated 50BMG case that has been necked down to take a 30 cal projectile. There were 320 of these cases made to have a few different projectiles loaded and meant to be fired at Aberdeen for testing (HWS vol II - pg 237 -[Thanks Ray!]). This one is loaded, with live primer and original projectile. Headstamp is FA 42
No tip color on bullet. The projectile is non-ferrous, and the case contains no powder, but the crimp and primer appear original. Has a couple weak green spots on case which could be removed. One condition issue is a pair of small dimples near the neck. They do not puncture through, and I don’t know what they are from. These are rare to find in original unfired condition apparently. Make an offer.