Difference between Bisley Revolver and OM Blackhawk Revolver?

Most of you know that I recently purchased an Old Model Blackhawk in 45LC. I was looking the other day on the Internet for a nice carry holster. Some are listed in styles I want but some say, "It will fit" and or Bisley models also. What is the difference between the two Revolvers? Thanks!

Biggest difference is the shape of the grip frame.
There were no OM Bisleys made my Ruger that I know of. Folks may modify them but, thats a different story.
NM Bisleys come in different frame sizes from Single Six up to Blackhawk. Maybe even Vaquero, I don't know.

Bisley on top
Standard grip frame Single Six below

To answer the OP where a holster fit is concerned,,, no difference.

Bisley refers to the grip frame shape,, and the different hammer.

For your OM .45 Colt Blackhawk, just look for holsters that are for the "full size" Blackhawk. There are medium frame Blackhawks,, (the Flattops,) and the smaller framed Single-Six guns. Look at the picture above. It shows a full sized Blackhawk frame,, and the smaller Single-Six frame.

One I am looking at is GALCO SAO STRONGSIDE/CROSSDRAW BELT HOLSTER. Anyone else have any suggestions?

Well, not knowing your budget,, I'll throw out a few things for you to consider.

First off, I'm not a big fan of Galco. Oh, they have some good stuff,, but many years ago I tried to discuss carry/holster options for ladies with the management. I was politely told that "Galco isn't interested in that market." Of course,, later on, they did finally get into it.
That's a PERSONAL reason for myself to look elsewhere.

So, to offer a few different brands for you to consider, try looking at (2) different leather companies that are BOTH members here,, AND supported by many of us in the Ruger Fan club world.
In my humble opinion, by far the absolute best leather holsters I've ever had the pleasure of owning come from Mike "Doc" Barranti of Barranti Leather. Absolutely the best. You can buy from the "store" or have a "custom" made.
Next,, another good company and very good leather, is "Simply Rugged." Rob Leathy is also a good person & makes good holsters.

Check them out.

OK, Thanks!

When talking about NMBH, NMSBH and Bisley, large frame, revolver frames are identical on all of them, either blue or stainless. Of course, all main frames are from either, stainless or alloy steel (blue finish).

- You probably noticed differences in cylinders; fluted, nonfluted, nonfluted and roll engraved, and also, different triggers and hammers.

- Stainless revolvers have all parts from stainless steel.

- Blue BH have grip frame aluminum, ejector housing from alloy steel.

- Blue SBH has all parts from alloy steel.

- Blue Bisley has grip frame from alloy steel, ejector housing from aluminum.

Hope I covered main differences. Please correct me if I missed something.