Short Chamber in Open Top

[dangt]

 I am new to this forum but have been buying, shooting , and working on  guns all my life.  I recently bought a new Open Top 1871-1872 in 44 Special . I have run onto something I want to relate maybe just to see if anyone else has seen this.

My long experience with used guns makes me thoroughly check over something new to me before I shoot it. On this O.T. , I intended to check head space and mechanical function with primered-only cases.  I found that 44 Special rounds would not fully seat.  These primered cases were new, never fired R-P brass of consistent case OAL of 1.155?.  I could see a space under the rim when put into the chambers and the gate would not close on the round.  I loaded a live round with Lyman lead bullet and it would chamber fully.

Lots of measuring showed the chamber is shorter than SAAMI specs by more than .025 inches.  I did a search on this forum for comments about such a condition and only found a discussion of some if not all Uberti 44 Colt revolvers accepting  44 Special loads.  45Dragoon made the comment to be careful about an actually short chamber locking on the crimped case neck as it tries to open in firing. He did not specify but I know that would raise chamber pressure.

My own revolver is probably not unique.......there are likely more like it out there.  I am not going to fire full length 44 Special ammo without either reaming the chamber to greater depth or using shorter cases.   Right now I have plenty of 44 Russian cases and will acquire some 44 Long Colt empties. I really dont want to shorten the 44 Spec. brass I have since then I would have shorter than normal cases for my other guns in that caliber.  I wont mind having this Open Top as 44 Colt/Russian only.

Here's some pics.  The case marked ?P? has been crimped in slow progressive stages until it just fully seats.  The other case on the right is my normal crimp used with cast lead bullets.

[Abilene]

Is the barrel marked .44 Colt or does it include S&W Spcl ?  If it is brand new from Cimarron it certainly should be chambered for the Special.  I'm not sure how the loaded round could chamber if the cylinder was chambered for .44 Colt.  Might have to do with the way your cases are prepped?  See if a factory round will chamber.

[Crow Choker]

Curious 'dangt', you mentioned you used some new, unfired RP primed cases to check the cylinder fit. Were these some factory primed cases or new unprimed cases you primed and did you resize the cases? I've seen new both primed and unprimed cases that didn't meet proper cylinder and/or chamber fit. That's why I resize all new brass I buy. You advised a loaded round fits ok, that's why I'm asking. Being you put a crimp on the empty brass, that didn't put pressure on the brass somehow in putting an unseen bulge towards the base of the brass that isn't allowing it to fully seat in the cylinder? If loaded ammo with proper specs doesn't fit right, I'd not shoot it at all and contact the seller you bought it from. Just my thoughts!

[45 Dragoon]

 Dangt ,  glad you caught it!! I know folks are all the time saying 44 C chambers  will accept 44 spls but  .  .  . if that's true, why aren't they id'd as 44spl?  If a heavily crimped 357 mag can be accepted in a (over sized) .38 spl chamber, it's not good. To me , neither is a 44 spl in a too short chamber. Cowboy shooters might get away with it because of the loads they shoot but loads on the upper end might make a short day for some. There must always be room for the crimp to unroll in a proper chamber.
  I had a '71 OT for a while. I ordered a 44 spl cyl for it.

Mike

[Drydock]

That looks and sounds an awful lot like a .44 Colt chambered cylinder.  Be interested to know what the actual caliber marking is.

[dangt]

What I first wrote may have been confusing about having bought a lot of used guns.  This Uberti Open Top was new but it did not come from Cimarron.  Barrel is marked 44 SP and is numbered to the frame serial.  Box is also marked with the 44 Spec caliber.  Cylinder is numbered to the frame .too ( last four digits).  All six chambers have the same condition.

Cases used were New, unsized, un-primed.  Since in firing cases would expand to chamber diameter, I figured not being sized would make no difference. Just to be sure, after reading the above comments, I sized a case and found it still would not seat fully in the chambers. Again, these new R-P cases are 1.155 inches in length, well within SAAMI specs for this caliber.  Rim thickness is also of correct  dimension:  .054 to .055 inch.

I , too, am glad I found this.  This gun will not be used with anything but mild loads ( or at least NON-hot loads).   I see this short chamber condition could have been stressful but to what amount I cannot know.  I'll play it perfectly safe and use 44 Colt brass.

[Abilene]

Well, whoever you bought it from, if new should have a warranty.  I would call the importer.  They may have you send in the cylinder to have it reamed.  If no warranty, it should be inexpensive to pay a gunsmith to do the reaming.

[Crow Choker]

Well, whoever you bought it from, if new should have a warranty.  I would call the importer.  They may have you send in the cylinder to have it reamed.  If no warranty, it should be inexpensive to pay a gunsmith to do the reaming.

That looks and sounds an awful lot like a .44 Colt chambered cylinder.  Be interested to know what the actual caliber marking is.

What Abilene and Drydock posted. I thought also when I posted my first post that maybe Uberti got a 44 Colt cylinder on the Open Top 44 Special. I tired some unsized and sized 44 Special new Starline cases in the cylinder of my OT marked 44 Colt. Both varieties didn't seat fully into the cylinder. Looked like the picture 'dangt' posted with the rim and small portion of brass wall still protruding. I also inserted two loaded 44 Specials into my 44 Colt cylinder, one with a 200 grain cast and the other with a 240 grain cast. Both rounds seated fully into the cylinder as 'dangt' advised when he did it. Why this is, is beyond me, most likely due to the close dimensions of the 44 Colt and 44 Special brass. You'd think this couldn't happen. Could be as posted the uncrimped 44 Special mouth on the case is stopped by internal dimensions and a crimped loaded 44 Special cartridge is allowed to slip by due to the crimp making a slight smaller dimension. Someone with more background in why this occurs will have to explain. Sized and unsized 44 Specials fit perfectly in the cylinders of both of my OT's chambered for 44 Special.

Maybe Uberti just makes the 44 Colt and Special cylinder's to the same internal dimensions and just lists them as the calibers it does to satisfy the needs and desires of shooters. Boring cylinders to one dimension saves dollars to them not having to mess around with doing two calibers. I don't think this is so, but anything's possible. I know back in 2007 when I bought my first OT, a 44 Special Army, a Cimarron rep on the phone told me the 44 Special revolvers had 44 Colt stamped on the frames to satisfy shooters wanting to shoot 44 Specials, but wanted a revolver with the more 1800 era 44 Colt stamped on them. By the time I got my 44 Special Richards II in late 2008, Uberti stopped the practice and just stamped the actual caliber on the frame. I asked a Cimarron rep about this before I ordered. MY Richards II has 44 Spec on the frame. IMO not a good practice as leads to confusion to OT owners/shooters not aware of the practice.

Just for the heck of it, I inserted a loaded 44 Magnum round into one of my 44 Special OT's and it left around 1/8" of rim/brass outside the cylinder, which is a good thing, a heavy 44 Mag load would not be good in a OT revolver. I took several pictures of 44 Spec brass in the cylinder off of my OT marked 44 Colt showing the protrusion of the brass. When trying to post, I was advised my pictures had too much whatever. Tried to downsize with no luck. Part of the rewards for not growing up with these dang computers or having any formal training in how to do this and that. 'dangt', I'd ask to whomever you bought the gun from where they purchased it from and/or find out if from Taylor's or Cimarron and find out the 'skinny' on the gun. As Abilene advised, if new it should be under warranty and if there is a 'miss-cylinder', get it right. Ya lay down cash for a new warrantied item and if not right, ya shouldn't have to pay some one to fix it. Anyway, whenever ya get things figured out, the OT's and their cousins are a joy to shoot.

[dangt]

My Open Top came from Dixie Gun Works.  I do not know if they import their own Italian guns or if they get them from an importer. The box does NOT say Stoeger on it as I've seen on guns from elsewhere.  The box is marked AU where some other Uberiti boxes I've seen say Stoeger.

From other older posts I've read on this forum I have seen other suggestions that maybe all Uberti 44Colt and 44 Special cylinders are chambered to the same dimensions ..........as Crow Choker also suggests as possible.  The awful thing is, those single dimensions may actually be those for the Colt cartridge. My cylinder will accept a loaded 44 Special Cartridge yet is actually too short and maybe there are others like this, too.

If someone was "checking over, or inspecting" a gun before it was shipped out as I have read Cimarron does, I do not really believe chamber dimensions are thoroughly measured.      It might be believable that they try a dummy round for fit which just might fit in my gun apparently      since I can chamber a loaded and crimped round ( a loaded and uncrimped round would not fully seat). 

Crow Choker, you said your 44 Colt marked gun will accept loaded 44 Spec cartridges and that sized-only empties wont seat fully.  Did you also try a sized-only or new 44 Special case in your 44 Special.......  I think I read that you have both a Colt marked gun and a Special  marked Open Top?

As far as my own revolver goes, I do not intend to send it back nor to make any warranty claim.  I went to a local shop this morning and bought 100 rounds of Starline 44 Colt cases.  Careful measuring and trial fitting show, of course, that they will be fine in my gun.  I intend to just treat the revolver as a 44 Colt  with the different head stamps helping me to keep things straight.

[Crow Choker]

Yes, was going to mention it, but unsized and sized 44 Special brass fit completely into the cylinders of both of my Colts, a Open Top model and a Richards II (both chambered for 44 Special). As I penned, all I shoot out of them are my reloads. Loaded up some 44 Spec with 27 grains of FF blk vs 25 grains (44 Colt), but saw no advantage in accuracy, just more smoke and boom I imagine, but couldn't really tell much difference. As I penned, most of my 44 Spec loadings and shooting are done in a Ruger Super Blackhawk and I keep those rounds marked and stored away from my Open Top Colt framed ammo. When I did reload for the OT's using smokeless, I had good experience with Titegroup,, 231, Red Dot, and some TrailBoss. All using 200-240 grain cast bullets. The 200 grain Mav Dutchman is my favorite cast bullet using SPG lube.

44 Special ammo in my Colt OT types is rarely shot and those were loaded to mild 800 fps or so velocity. The 44 Special rounds I inserted into the 44 Colt cylinder were both reloads. I reload for most everything I shoot, except shotgun, 22 LR, and some 9mm and 45 ACP used for any possible defense needs. If you have no interest or desire to have gun checked or warranty filed, you'll have just as much fun shooting 44 Colt ammo as 44 Special. Are you going to reload/shoot black or smokeless in your OT? If you've never had a Colt Open Top style either percussion or cartridge, sometimes the timing needs a little TLC so the bolt engages the cylinder as it should and most all need some arbor adjustment, ie some length needs to be added to the end of the arbor so it has a tight fit in the barrel assembly.

[dangt]

 Crow Choker,

Thanks for the reply.

This is my seventh open top Colt replica plus an original 1851 that I no longer have.  This Open Top is the first factory made "conversion type" using cartridges .  I converted one percussion gun before the O.T., a Centennial Arms 1851 converted to 38LC, a couple of decades ago. So I am familiar with lots of open top design "stuff"  and peculiarities.

Before the days of the internet, I never read in magazines (the only real source of info for me) anything about the "short arbor problem."  I just learned early on  how much pressure to use on a wedge to get the function of everything that was needed.

[Crow Choker]

Good enough 'dangt'!!!! Thought I'd ask just in case. I started shooting a percussion open top style Colt back in '72. I never really heard about the arbor issues until I started reading the CAS forum back in early 2009-just never talked to anyone about it, nor read anything in publications I had access to. A lot of good info in the back pages of this forum.

[Abilene]

dangt, the short arbor thing is sort of a "fine tuning" thing, partially for consistency, partially to reduce wear.  Supposed to reduce battering of the slots and wedge.  I've got thousands of rounds through 4 Richards-Mason conversions before I ever heard of the short arbor.  They still worked fine but the wedges were in pretty far.  I dropped a washer down the arbor hole in the barrel (the quick and easy fix) and it tightened them back up.

[Galloway]

See all the fun gripes you fellars been missing out on cause you were too busy shooting and enjoying them lol!!!!

[Coffinmaker]

  HI EVERYBODY   

FIRST things first!!  It's the last day of the "Teens."  The END of the DECADE.  We are about tp enter a brandy Knew Edition of the "Roaring Twenties."  How Bout Dat!!

OK.  I've been playing with Open Tops since they were first introduced by Cimarron and were a Cimarron Exclusive (Didn't last long).  My personal guns are reputedly the pair of guns sent to all the scribes for their proclamations, chambered in 45 Schofield.  I actually became sort of the "Open Top Guru" in my sphere of influence, and with all the work I've done on Open Tops, I've seen it all (mostly) and it is not at all uncommon for .44 Open Top guns to NOT be as marked.  I've seen guns marked 44 Colt, would chamber .44 special just fine, guns marked 44 Special that wouldn't chamber anything longer than 44 Colt.  Really crazy stuff.  I have NEVER seen Uberti Open Top guns with correct Barrel to Arbor fit and have always advocated fixing that if you wanted the guns to run right.

.44s have been the big problems (Except for .45s) and you have ALL related the mishmash of really knutson chamber dimensions.  My only council to folks with .44s is to CHECK THE CHAMBERS then run whatever cartridge the gun wants.  I have never seen the cylinders with cartridge stamps.  Good Luck.

[Marshal Will Wingam]

... I have NEVER seen Uberti Open Top guns with correct Barrel to Arbor fit and have always advocated fixing that if you wanted the guns to run right.

I'm not really knowledgeable about the open top designs. I read about putting washers in the arbor to space it out a bit. How do you know when that is needed and how can you tell how thick a spacer (washer) will do the trick. My Pietta 1851 in .44 with a .45 conversion cylinder shoots very high. Like 4' high in maybe 15 feet. I can't recall exactly how high it does shoot but it's something bizarre like that. Will setting up the arbor correctly take care of this issue?

[Coffinmaker]

Marshal Will,

There is a very good chance your Pietta has correct Barrel to Arbor fit.  Pietta fix'd that a long long time ago.  However, to check the fit, turn the barrel 90 degrees off center, shove the arbor in till it bottoms out, then turn the barrel back.  The back of the lug should align right at the front face of the frame water table.  It may be really stiff if you haven't polished the burrs off the Arbor and out of the Bore in the lug.

Normally, Pietta and actually any of the Cap Guns will shoot very high out of the box.  That little nub of affront sight (sorry thing) is sort of "on" at 75 - 80 yards.  It's way SHORT!!  Even after fixing a Uberti short arbor, they will still shoot high.

[Marshal Will Wingam]

Marshal Will,

There is a very good chance your Pietta has correct Barrel to Arbor fit.  Pietta fix'd that a long long time ago.  However, to check the fit, turn the barrel 90 degrees off center, shove the arbor in till it bottoms out, then turn the barrel back.  The back of the lug should align right at the front face of the frame water table.  It may be really stiff if you haven't polished the burrs off the Arbor and out of the Bore in the lug.

Normally, Pietta and actually any of the Cap Guns will shoot very high out of the box.  That little nub of affront sight (sorry thing) is sort of "on" at 75 - 80 yards.  It's way SHORT!!  Even after fixing a Uberti short arbor, they will still shoot high.

I checked the arbor fit and assuming I measured correctly, there is a difference of about .008 between the barrel on the frame and with it rotated off. Can that be enough difference to have it shoot as high as it does? That's certainly not enough to have room for a washer to drop in there but maybe I could find some brass shim material if needed. I'm probably looking at having to put a tall blade front sight on it.

[45 Dragoon]

Marshal, what you're actually looking for (in the end) is a .0025" - .003" endshake.  I normally call it barrel/cyl clearance. It's not a gap (a defined opening) because the cyl kisses the barrel each time the action is cycled.
  In the case of a Pietta, if the endshake is .008" (your measurement) that's a little much for me. Closing that down (removing material from the arbor) will have the effect of tilting the barrel up ever so slightly. Having to add material (to the arbor or the arbor hole end) which will ultimately "open" the bbl/cyl clearance to arrive at the desired clearance will tilt the barrel downward (ever so slightly) .
   The two possibilities mentioned above will shed light on what will happen when you "fix" the arbor situation (too long or too short). The "fulcrum" (in our interest ) is at the barrel lug/frame, the adjustment of the arbor length is what determines the clearance (endshake) of the cylinder (and ultimately the "tilt" of the barrel) which will remain constant after the "fix" is done.

Mike

[Marshal Will Wingam]

OK, then. I'll have to shim the arbor to get that correct before doing anything else. That is obviously the place for me to start. Thanks for the direction.