I'm looking at buying a Marlin 1894 Cowboy in 45 Colt. After going through various people and companies that make cast bullets I've found different outside dimensions. I went onto Marlins sight and cant find anything stating the actual bore diameter. Unless I'm blind.
Cowboy 45 Colt - slugging a barrel
- Thread starter 358Scout
- Start date
Cast bullets do seem to come in a small range of sizes. But being soft lead I would not worry about it. Some that have lots of lube grooves will sometimes be sized a thou or so bigger as they know the lead will swage to the barrel upon firing the round. Some others will match to the "spec" size just because that's what they do.
As I understand it all bullets will do something called "obdurate" when fired and as they enter the barrel under the pressure of the round. While the definition of "obdurate" has nothing to do with guns from what I've found shooters use this to describe how a bullet is pressure formed into the barrel and out into the rifling grooves. So sizing doesn't need to be accurate down to the quarter thou. The bullets are fluid enough under the pressure of firing that they will be formed to fit the barrel as they transition from the case and chamber into the beginning of the rifling.
As for bore size there's actually two dimensions. One for the inner "minor" size to the crest of the lands and another "major" diameter to the valleys of the rifling. I've seen well detailed specs give both or one plus rifling depth.
As I understand it all bullets will do something called "obdurate" when fired and as they enter the barrel under the pressure of the round. While the definition of "obdurate" has nothing to do with guns from what I've found shooters use this to describe how a bullet is pressure formed into the barrel and out into the rifling grooves. So sizing doesn't need to be accurate down to the quarter thou. The bullets are fluid enough under the pressure of firing that they will be formed to fit the barrel as they transition from the case and chamber into the beginning of the rifling.
As for bore size there's actually two dimensions. One for the inner "minor" size to the crest of the lands and another "major" diameter to the valleys of the rifling. I've seen well detailed specs give both or one plus rifling depth.
