38 VS 9mm barrels Qs.

[pred]

I am wondering about what the difference is between the 940 (9mm) barrel and a 38 special barrel?????
I have seen one or two around here get their cylinders set up for 9mm from 38sp, but I never hear about swapping barrels,,
Thank you for any info you may have!
Peter.

 

[pred]

I am wondering about what the difference is between the 940 (9mm) barrel and a 38 special barrel?????
I have seen one or two around here get their cylinders set up for 9mm from 38sp, but I never hear about swapping barrels,,
Thank you for any info you may have!
Peter.

 

[shovelwrench]

.001 difference, they are damn near direct replacements for each other.

 

[David Manson]

SAAMI lists bore/groove specs of 346"/.355", respectively for the following calibers: 357 Mag/Max, 38 Special, 9mm Luger, 38 Super. Tolerance for bore/groove diameters is plus .002", minus .000". Different bullet diameters have traditionally been used with the above calibers, but the nominal bore/groove dimensions are the same.

Hope this helps.

Dave Manson

 

[tomcatt51]

The "problem" is probably the cylinder throat diameters. The throats will probably be too big for real accuracy with the smaller diameter 9mm bullets. For the purposes of a snubby I suspect it's a non-issue.

 

[bountyhunter]

Originally posted by shovelwrench:
.001 difference, they are damn near direct replacements for each other.

Close enough that any effect on accuracy (if there is an effect) would not be seen by most shooters.

I wish I had a 9mm conversion cylinder for my 66 so I could shoot cheaper ammo.

 

[pred]

Thank you for the info, It sounds like the gun will be more accurate than me!
I have a 940 cylinder on the way to me along with a 3" 9mm barrel to match. I am thinking about taking a 649, and making it a 3" 939.
Thanks for info!
I would also like to keep the 38 special cylinder and be able to run rounds through the 9mm barrel!
Peter.

 

[badwhale]

You should be able too.

Where'd you get the 940 cylinder?

I'd like to get another to ream to .38 super, and still have my 9mm cylinder.(I know, you can ream it to .38 super and still use 9mm)

 

[HEADKNOCKER]

David Manson above reamed my 940s cylinder to 38 Super & beveled the charge holes as well.
What a Nifty Piece of Machining Work..
Thanks Again David!!
Gary