Cylinder question

Since I do not have an old model 30 carbine in the safe I hope one of you folks can answer a question for me. How does the OAL of the OM 30 carbine compare to the OAL of the OM 44 flat top cylinder? I am wondering if the 30 carbine cylinder is long enough to to fit in the 44 flat top if it rechambered to 44 Special and or 44/40. Hopefully one of you guys like Hondo44 or Rugerguy might know this.

Thank you for the help,

Robb

I have both Robb, but in MN now. Home tonight and will measure if no reply by then.

Thank you Malcolm.

I just compared my OM .44 Flattop with my OM .30 Carbine.

The cylinder of the .30 Carbine is 0.015" SHORTER than the cylinder of the .44 Flattie. Yes, the .30 cylinder will go into the .44 frame, but the face of the cylinder contacts the rear end of the barrel, leaving that gap between the cylinder's gas ring and the frame.

And of course the .44 cylinder won't go into the .30 frame at all.

OM 30 is 1.747 for cylinder and 1.959 overall
OM 44 FT is 1.750 for cylinder and 1.975 overall.
30 cylinder fits in 44 frame with .0015 cylinder/barrel gap.

OM .30 is 1.746 for cylinder and 1.966 overall.
OM .44 is 1.748 for cylinder and 1.981 overall.
When .30 cylinder is put into .44 frame there is considerable cylinder/barrel gap and even more gas ring/frame gap . . . when cylinder is pushed forward til it touches back of barrel there is still considerable gas ring/frame gap. No good.

So, you have the information you requested? Hope all info was helpful. But I suspect nothing like having both in hand.

Thank you gentlemen, that lets me know what I need to know.

Robb

Robb Barnes said:

Since I do not have an old model 30 carbine in the safe I hope one of you folks can answer a question for me. How does the OAL of the OM 30 carbine compare to the OAL of the OM 44 flat top cylinder? I am wondering if the 30 carbine cylinder is long enough to to fit in the 44 flat top if it rechambered to 44 Special and or 44/40. Hopefully one of you guys like Hondo44 or Rugerguy might know this.

Thank you for the help,

Robb

Click to expand...

Years back a friend, who had 3 screw 30 Carbine and 44 magnum Flattop, tried to swap cylinders. Fit and cycling were perfect. Of course, this was pure luck, but dimension difference should be minimal in any case.

In that respect, a good smith should not have a problem installing 30 Carbine cylinder on 44 Magnum Flattop, and reaming to either 44 Special or 44-40.

Bowen sells Ruger Endfloat Bushings in the online store under Miscellaneous Parts. They easily address the gas ring gap issue. Takes a few minutes with a lathe (and a lathe operator - I watched Hamilton do one, pretty slick) and you can set the gap to whatever you like. Barrel set back takes care of the rest of the problem, though you might have to face off a little on your original stock fitted cylinder to fit with the reset barrel.
Go for it Robb!
Tim

Well that sounds like it can be made to work fairly easily. The cyl body length can be faced off for a proper bar/cyl gap. And the gas ring can be replaced or tig welded and refit to the 44 frame.

As I recall the OM 30 cyl has recessed chambers. So the 44 spl can be partially recessed or the rear of the cyl faced off.

OM .30 does NOT have "recessed" chambers.

May be other work necessary as well. I put my OM .30 cylinder into my OM .44 Flattop, and in addition to the length hassles I mentioned above there was no way the cylinder would cycle properly even when held firmly to the rear to insure proper "headspace" and pawl engagement. I didn't make any effort to remedy this, just pointing out that it may or may not be an issue once the cylinder length is resolved.

There's very likely enough difference between various individual guns & cylinders to present situations we haven't addressed.