Open Top 44 Chamber Depth

gunboat57 · December 05, 2024, 01:51:12 PM

Hi all.
I bought an Uberti Cimarron Open Top Colt replica a couple years ago. Barrel is marked 44 Colt, Russian, Special. I developed loads for it using 44 Special brass which were on the short end of SAAMI specs for that cartridge length. Then I got some new brass which is at the middle of the SAAMI spec for length. That new brass won't seat in the chambers. I did some careful measuring and found out that the distance from the back of the cylinder to the "shoulder" in each chamber is about .030" too short.
My question is can I just get a reamer, about .458" diameter I think, and deepen the chambers .030" using my drill press? Is the steel of the cylinder hard enough to need a carbide reamer?

Abilene · December 05, 2024, 01:59:00 PM

When I worked at Cimarron we would ream cylinders by hand from 44 Colt to 44 Special. I think it was a Clymer reamer, not positive, with a T-handle. It was pretty easy.

Hair Trigger Jim · December 05, 2024, 02:25:04 PM

I would think it would be too easy to mess up a chamber with a drill press.

Coffinmaker · December 05, 2024, 08:32:14 PM

Gunboat57

PLUS ONE FOR Abilene and HT Jim. When I still had my shingle out, I worked on a veritable pile of Open Top guns. Recutting the .44 chamber to accept 44 Special cases was a pretty common job and I used a reamer from "Manson Reamers." IT'S A HAND JOB!! Skip using a drill press unless you're very adept at building precision jigs. It won't take long at all by hand. OR:

Unless you plan to shoot 44 Special in some other gun you might consider just shortening you new cases to match your old cases?? That won't take long either. Always work on the CHEAPEST pieces FIRST.

gunboat57 · December 06, 2024, 05:45:06 AM

Sounds like renting a hand reamer might be my best bet. I'll look into it.

As a quick alternative, I just ordered 100 pcs of 44 Russian brass. I'll see what kind of accuracy I get even though my chambers might be a bit long for the Russian.

Really like my Open Top. It came with the Navy grip frame but I bought an Army grip frame for it. With my "short" 44 Special brass I was getting "ragged hole" accuracy at 25 yds off a rest.

Coffinmaker · December 06, 2024, 10:06:31 AM

Gunboat

I must share, just a thought or three. My favorite cartridge in my Open Tops with the .44 Cylinder/Barrel combo is the 44 RUSSIAN. I usually load it (the Russian) with 160Gr RNFP, either plain or coated, sized .430, over 3F APP. I get fine accuracy. Doesn't seem to care about that little jump from case mouth to the Throat. I would suggest, with a .429 bore, you might consider insuring your cylinder throats are at about .430.

And Bye the Bye, Uberti has been famous for cutting the Open Top .44 chambers "Short." Although I also found it not uncommon for an Open Top marked .44 Colt to freely chamber 44 Special cases. It's really a crap shoot. Also as a funner, My Open Top Barrels, Ordered to run with my .44 Cylinders arrived roll marked .44-40. Uberti has never manufactured an Open Top in .44WCF/44-40. Go figure.

Abilene · December 06, 2024, 10:47:16 AM

Quote from: Coffinmaker on December 06, 2024, 10:06:31 AM...Also as a funner, My Open Top Barrels, Ordered to run with my .44 Cylinders arrived roll marked .44-40...

You've mentioned that before. Pretty big mistake! You have to figure there's probably more of them out there somewhere. Yeah, Uberti do make mistakes. I've seen cylinder caliber not matching barrel (that could be bad!) and smooth-bore barrels that would run afoul of the feds if they caught it!

gunboat57 · December 06, 2024, 02:59:14 PM

Coffinmaker, that's good to hear about your results with 44 Russian in your Open Top. I'll be working up a load using 200 gr RNFP sized to .431 dia.
I checked my chamber mouths and a .431 bullet will just pass through with a light push.

Coffinmaker · December 06, 2024, 05:43:21 PM

Gunboat

Were you standing at my counter, I'd be telling you "Your Gold" and to skip paying me to ream either your chambers or your throats. My suggestion is to run the gun "as is" with Russian cases and save yourself a goodly chunk of change. Enjoy the gun!!

gunboat57 · Reply #9 - Re: Open Top 44 Chamber Depth

Followup: my 44 Russian loads group about an inch at 20 yards off a rest. That's pretty good for my old eyes.

Cimarron said I should send the revolver back to them for evaluation and possibly fitting a new cylinder actually cut for 44 Special. But I'll just keep it as is for now.

Someday if I can borrow a 44 Special reamer, I might just take out the .025" of material myself.