10mm vs. .40 in revolvers

[John D]

I have a Ruger Blackhawk convertible (well, two actually) in .38-40/10mm. As this is a single action, the 10mm cylinder doesn't use moon clips, etc. - the cartridges just drop into the chambers.

I haven't tried shooting .40 in these guns, so I don't even know if the firing pin would even strike the shorter cases. I usually shoot .38-40 rounds and only recently got the dies to load 10mm. But, I have noticed that when I shoot 10mm, the cases "clip" a little and tend to jam up the end of the cylinders after several rounds - so much that you have to clean the cylinders before you can continue shooting.

Any thoughts about shooting .40 out of the 10mm cylinders?

 

[sw627pc]

Won't work John. The S&W 610's can do it because they use moon clips which hold the cases up. In a SAA the .40's will drop down into the cylinder. Probably far enough that the firing pin won't hit them. If they did fire, the case is going to get slammed back and you are most likely going to have blown or pierced primers and a face full of hot gas.

 

[Intel6]

In the single action Ruger, the rim of the case keeps the case positioned for proper ignition. With a rimless case like the 10mm the case it held in position by the front edge of the case stopping at the front of the chamber like it does in an auto. If you try using a shorter case, it will slide into the chamber until the case mouth hits the end of the chamber. When it does this it won't fire so using 40 S&W in you Ruger will not work.

Where the 40 S&W can be used is in the S&W 610 revolver. Since the moon clips keep the round properly postioned, it doesn't rely on the length of the case.

 

[John D]

Yeah, I figured this is what would happen (which is why I haven't tried it). I like the "snap" of the 10mm round, although the .38-40 is very comfortable to shoot and fun (well, a challenge) to reload...very satisfying.

Speaking of convertibles, I know that Ruger made a .44mag/.44-40 convertible at one time. If I could get my hands on one of the .44-40 cylinders, wouldn't I be able to swap that out with my Super Blackhawk .44mag cylinder? And, if so, how would I obtain one of these?