1 in 16 would be excellent for the heavier bullets.

Some time ago, someone printed an add for eitehr Marlin or Winchester (couple years ago) saying they had 16" twists, but turned out it was a misprint - or lie - whatever the case may be and were still sitting on the 38" twist. Don't get me wrong, the 38" twist will shoot the light bullets just fine, and even heavier in 45 Colt if you can get them moving.
I've just prefer a faster twist. Sure was a fun gun to shoot in .45 Colt. I found RP brass the strongest of all US brands. I found Fed to be considerably weaker. I do not know about Startline brass - that's new to me.