I've generally settled on two lead-bullet loads -- both using H110/W296.
One uses the 255gr Keith (plain-base/LSWC) over 24gr; and one use the 340gr Beartooth (GasCheck/RN-FlatPoint) over 21.5gr. Both are at the low end of the "Ruger-Only" pressure spectrum as listed by Linebaugh (for the 255 Keith) and the Hodgdon site for a 335 LSWC.
Both bulge cases in the Marlin`94 chamber:
I was initially somewhat concerned until reading up the experience of others, and then examining the SAAMI specs of both the 45 Colt case as compared to the relatively sloppy chamber dimensions:
the measured base
/web of the new Winchester cases is 0.475" When resized in my carbide dies the web diamter ahead of the base is 0.477-ish.
When fired in my`73 Ruger BlackHawk the diameter just ahead of the solid base expands to 0.483(+) but the expansion is symmetrical due centering in the cylinder and unremarkable. When fired in the Marlin
and held to one side of the chamber by an extractor, however, the expansion is unilateral (and more noticeable). Others who play the rifle game have noted this is standard fare in higher-pressure 44s and 45s, and not to get too excited.
I've got a Redding dual-stage carbide sizer back-ordered from Midway to reduce the effective sizing action on the case near the web, but it may still turn out that I have to toss cases after a set number of firings like I do on the M1A. Anyone else have related experience here?
(Meanwhile, the 255s are printing barely an inch at 50 yards after I got a Williams aperture sight on it.)