I have basically settled on two loads for my M97s in .45 Colt.
1. RCBS 270 SAA (usually weighs about 280+ gr). Available from Montana Bullet Works, Lynn AHalstad (Dry Creek Bullets), and Mt Baldy. Mt Bullet Works and LAH will size to your requirements.
I load this bullet over 8.0gr of HP38 and crimp on or over the front drive band to achieve 1.600 OAL. My size die provides sufficient case neck tension to taper/slight roll crimp on the front drive band with no bullet movement.
This load runs right at 900 fps, 5 steps from the muzzle from my 4 1/4" FA97 and in my gun is very accurate. Crimped over the front drive band, this load shoots one hole groups from my FA83 (when I'm up to it).
2. 300gr SWCGC RCBS (82023) from Montana Bullet Works. The ones I have from Mt Bullet Works weigh right at 320gr With care, this bullet can be crimped in the crimp grove and still function in the FA97 cyl -- it is however right at the face of the cylinder and any bullet movement will cause problems. You can also crimp over the front drive band -- I have done both.
I use 21.5gr H110, CCI350s in Starline brass. I get 1,100 - 1,150 fps (depending on individual lot) at 5 paces from the muzzle in the 4 1/4" FA97. This is the most accurate load I've found for my gun. At 25yds, this load prints about 1" higher the the first load mentioned above with my hold.
The first load is the one I use 90% of the time and can be shot comfortably all day long.
Montana Bullet Works
http://www.montanabulletworks.com/45_Colt.htmlMt Baldy
http://www.mtbaldybullets.com/Dry Creek Bullets
lah@suddenlink.netPaul