This is one gun that is NIB (no I do not want to sell it). I have always heard that the 45 LC can have different bore diameters. Should I be assuming that the bore for the gun is the smaller of the 45 ACP or 45 LC? I am waiting to get a lever action rifle before taking it to the range. Just an incentive to keep looking for the rifle. I have loaded some 45 LC and they are just stilling in the box.
I believe that Ruger goes with the larger bore spec of the two calibers. Much like in the .3579mm. There are some reviews of the smaller caliber being less accurate due to being undersized for the bore, but I've never noticed a difference in mine or the .357/9mm I used to have.
We have loaded some .451 diameter ACP 230 gr ball in some 45 Colt brass and I have shot them in my Colt and Great Western single actions. I can't tell any difference but you might be able to tell a difference in accuracy in a rifle.
I just looked on the Missouri Bullet website and for Cowboy guns the only diameter they show is .452 for handguns. Really did not see any 45 rifle bullets.
From Wikipedia Specifications Case type Rimmed, straight Bullet diameter .452 in (11.5 mm) Handloading[edit] Colt .45 revolvers made until early WWII had barrels with .454" groove diameters. After this diameters of .451–.452" were produced. Using .454" diameter bullets in the smaller barrels will work but will generate higher pressures. Cases used with .454" bullets may have to be full length resized to work in newer guns.[11] Speer handloading guidance states that the loads they show should be used only in handguns made specifically for modern smokeless powder. The loads mentioned in No. 10 reloading manual state that they do not exceed 15,000 psi. This is the equivalent of +P loading as normal pressure for the .45 Colt is 14,000 psi.[11]
The cylinder throat diameters are the problem area for the older Rugers. An easy check is to place the base of the bullet in the front of the cylinder to if it will easily pass. If it does you need a bigger bullet, the bullet must be an interference fit to the cylinder or your bullets can be gas cut if lead or suffer from gas leakage, cast or jacketed.
Sorry, don't know the year for certain but the first updated Rugers I handled were about 20 years ago.
I've had a .45 colt NM Blackhawk from 04' and a .45colt/acp from 16' and a NM Vaquero. 45acp birdshead and they all had throats at .450-.451" I reamed them out with one of the reamers from brownels to .4525" I don't have a crono and didn't shoot them before so not sure if/how the smaller throats affected bullets.
I have fired a friend's blackhawk in .357/9mm and found it to be a tack driver. I am a fan of .45 cal; is the .45Lc/.45acp also accurate as heck? Haven't had a chance to fire one, but it's on my short list of things I want. Just wondering...