Howdy I'll tell you a funny story. When I was in my 20s, back in 1975, I wanted a Ruger Blackhawk. And it had to be chambered for 45 Colt. So I found this one in a local shop. 45 Colt and 45ACP cylinder. The price was $150, which was a lot of money for a kid in his 20s in 1975. I was really only interested in 45 Colt, I could buy reloads pretty cheap, I simply was not interested in the 45 ACP cylinder. So dumb kid that I was I asked the dealer if I could buy it without the ACP cylinder for a little bit less. He looked at my like the idiot I was and said no, I had to buy all or nothing. So I coughed up the entire $150. I get a kick out of all the guys who tell you how much cheaper it is to shoot 45 ACP than 45 Colt, but the fact is I never fired that ACP cylinder until about 10 years ago. Shot a box or two, then put it away and have not used that cylinder since. No, it is not for sale. Don't even think of buying a revolver chambered for 30 M1 Cabine unless you get a chance to shoot one first. Talk about a deafening round fired from a revolver. Yes, you can run Ruger Only loads in every Ruger. Let me restate that. You can run Ruger Only loads in any modern New Model Ruger single action with a transfer bar. I would not try it in an old Three Screw. So I don't have to type it all over again, see what I had to say on this subject just a few days ago. Pay particular attention to what I say about the location of the locking slots on the cylinder, compared to a Colt or Smith and Wesson. Even though my comments are about a Ruger double action revolver, the same holds true for the position of the locking slots, and hence the strength, of a Ruger single action cylinder. https://www.thehighroad.org/index.php?threads/da-6shot-45-colt-high-pressure-recomendations.866237/ Look very carefully at this photo. Left to right is a Ruger 'original model' Vaquero cylinder, a New Vaquero cylinder, and a 2nd Gen Colt cylinder. All chambered for 45 Colt. The 'original model' Vaquero is not made any more, but the cylinder dimensions are identical to the a standard Blackhawk cylinder. Don't just look at the thickness of the metal between the chambers, look at the position of the cylinder locking notches. On the Colt, and every replica of the Colt, the deepest part of the locking slot cut is directly over the center of a chamber. That is actually the weakest part of the cylinder, not the thin cross section between chambers. There is less metal there than anywhere. If a cylinder bursts, the rupture usually starts there, and then propagates along the length of the chambers. Notice how on both Rugers, the deepest part of the locking notches are not centered on the chambers. Ruger purposely moved them a little bit, so there would be more metal between the chamber and the deepest part of the cut. Most shooters are not aware of this subtle change Ruger made when he added the transfer bar.