FWIW I've run about 2000 rounds of Bear Creek 230 Flat Points through several polygonal and conventional 45 barrels, with excellent accuracy and next to no deposits of even the coating in the bore.

https://www.bearcreeksupplybullets.com/aboutourbullets

When I was loading Montanas they were jacketed, so can't help you there.

Direct Impingement is the Fart Joke of military rifle operating systems. ⓒ