Unfortunately the ogive on the 275gr is to low and the bullet could not be seated out far enough to taper crimp and still fit in the magazine. In the profile pic attached the crimp mark on the 300gr (left) seated at 1.580” can be compared to the ogive on the 275gr (right).
I did load a few of the 275gr over 34gr of H110 and as expected, on chambering the round the bullet moved forward in the case because of the lack of sufficient crimp, by up to 0.015”. Velocity was low at 1105fps with es of 117, not sure if this was due to the crimp issue or the Winchester primer not having enough puff. I will be switching to CCI 350 in future for .50ae.
Despite these issues the gun cycled reliably for all 10 rounds.
I will be sticking to the 300gr from now on in .50ae. The remainder of the bullets will be tested in the .500s&w. Going to try 18gr of Unique and 43gr H110 see if either will make a good plinking load.
