NMA 58 Pietta/Uberti bore differences

[Moptop]

I have a Remington 58 made by Uberti which I love dearly. It is a newer one in their Mellenium matte black finish. It shoots perfectly, very accurate. Anyway, I recently aquired another Rem 58 this one being made by Pietta. . Although I purchased it a pawn shop it was very obvious that it had never been fired. I bought this with intentions of cutting it down to 5.5". I have always wanted a "shorty 58" and figured this was a good canidate for a project gun. When I got home I couldn't wait to compare it with my Uberti and noticed right away one BIG difference between the two. The rifling on the Pietta has less than half the groove depth then the Uberti. I thought "what in the world is going on here?" Why would these two be different in that respect if they are supposed to be replicas of the same pistol? Has anyone ever heard of this before?

Anyway, I put it away and didn't give it anymore thought......untill I took it out that weekend and fired it. It performed perfectly in operation but in the accuratecy department...it was horrible. It was all over the place! Now I only tried it with a 25 grn charge and .454 ball, which is what I normally use...but holy cow, it was bad. Now before I make a final decision on this I am going to try a few different charge sizes, and maybe a .457 ball to see if I can find it's sweet spot. I just don't want to waist time customizing a pistol that's not going to shoot well. Any suggestions on what to try?

So what do you think guys? Are Pietta's that much junkier than Uberti's or did I just get a bad one? I can't believe that there can be so much difference in quality between the two when I've heard such good things about them.

[Hellgate]

Check the CHAMBER diameter. My experience has been that the chambers are often too small which sends an undersized ball down the bore. The simplest solution is to ream out the chambers to about a thou over groove diameter then choose a ball diameter that is about 3-5 thou over the diameter of the CHAMBERS so they fit snugly. Whether you load a .451, .454, or .457 ball they will all get shaved down to the diameter of the chambers when rammed in. The larger balls will have more bearing surface and might just "bump up" as they enter the forcing cone and shoot more accurately. I shoot .454 balls in my two Millennium Ubertis as well as the various makes of colts and Remingtons. I no longer have any Pietta Remingtons but they were bought back when there was less QC (the 3 were all SS and had alignment issues with the chambers & bore. The original C&B revolvers had pretty shallow grooves down the bore so shallow is OK and is probably easier to clean. My late 1960s Uberti '61 Navy has very shallow grooves and is fine accuracy wise. The one original Colt I've peered down the bore on had a shallow progressive twist.I don't know for sure if the Remingtons were the same back then.

[Omnivore]

Mop; Yes, the Piettas have smaller chambers and different bores, but it's like pulling teeth to get reliable specs from the makers or from the vendors.

What do you mean by horrible accuracy? I have a Pietta Rem NMA and the best I've been able to do is an average 5-shot group of around 4 to 5.5" at 25 yards. That's with either .457" ball, 180 grain Buffalo Bullets, or 200 grain Lee .450-200-IR home cast bullets. Doesn't seem to matter what projectile, among those three, and the charges I use run from 28 grains to 40 grains of 3F Goex. Maybe it's not a reflection of the gun's limitations, but of my own. The heavier bullets run in the larger of those groups.

Word is, the original NMAs had progressive rifling, which none of the cheaper repros have. Pietta makes what they call the "Shooter's" model - a Remington NMA repro with progressive rifling, for close to 700 dollars. Dixie Gun Works' web site lists it for $675.00 at the moment. Sometimes Dixie gives you the bore and chamber specs, sometimes one or the other, and sometimes none. Most vendors give you nothing. I guess you’re supposed to buy one of each available make and version, try them all, then send back the ones you don’t like.

I measure my Pietta NMA chambers at .447 to .448" -- definitely smaller than the barrel's groove diameter.

[Moptop]

Thanks guys for the info on the Pietta Remmie's. I'll mic the chambers and slug the barrel and see what they are then maybe I can do a little adjusting to the chamber size and get her shooting tighter.

Omnivore, you asked what I meant by "horrible"....well I couldn't get any shots to land on the paper at 25 yards. At 21 feet there was no consistancy at where the shots where hitting......if that helps. With my Uberti, at 25 yards, I can keep them all in about a 4 to 5 inch group. It really does shoot that well.

If I have to increase the chamber dia a bit, what would be the best way to do it? Is there such a thing as a chamber reamer? I do have a drill press so I should be able to do a decent job without too much trouble.

Oh, on compairing the Pietta and the Uberti, I also noticed that the Pietta's cylinder is longer and slightly larger in dia. They will not interchange between gun frames. Once again I find this odd since they are supposed to be the same pistol.

[Omnivore]

There are some on here who've reamed their chambers. I haven't. I have used reamers for other purposes, and it turns out a 29/64" reamer is about right - .453". Lots of the on-line tool suppliers sell reamers. A regular, straight bladed reamer can do a nice job, and you don't have to ream all the way down the chamber. Just make sure you have everything aligned. Don;t do it without talking to those who've done it. Better yet go to a gunsmith who does this in a regular basis. Any 'smith who does extensive work on revolvers will probably have done this.

My Pietta, made circa 2007, shoots about as well as your Uberti, whether with round ball or 200 grain conicals. If that other Pietta doesn't, there must be something damaged, or it's out of time.

According to some writers, the Pietta, with the chamber being smaller than the barrel groove diameter, can shoot pretty well. My experience seems to agree. Still; it sure seems like an odd way to build a revolver.

Another difference is the Pietta frame doesn't allow for use of conicals unless you modify it. I believe the Uberti will take at least a 200 grain shoulder-base conical with no issues.

In other news; on advice from Dixe Gun Works, I chamfered all the chamber mouths on one of my Pietta cylinders, so I no longer get any lead shavings. Much nicer to load, without the shavings getting all over everything. Seems to shoot just as well as before. I have yet to test it from a bench, and so far I've only use the Lee .450-500 conicals in it. If it works well with both round ball and conicals, I'll then chamfer the chambers in the other cylinder.

[72coupe]

I have a Lyman 1858 Remington that came as a kit. Does anyone have any idea who made this?

It shoots amazingly well as long as it is not me shooting it.

[kaido93]

#6
72coupe
Senior Member



Posts: 126 I have a Lyman 1858 Remington that came as a kit. Does anyone have any idea who made this?

It shoots amazingly well as long as it is not me shooting it.



I called Lyman several months ago the tec explained that Uberti made their Percussion Revolvers.

[72coupe]

Thanks Kaido.

[rivraton]

The rifling on the Pietta has less than half the groove depth then the Uberti.

The rifiling only has to be deep enough to impart a spin on the ball..
Italian replicas (both Piettas And Ubertis) often have timing issues (the likley culprit) not really that difficult to remedy by working over the bolt position.

[Smokin_Gun]

MopTop check your chamber to bore alignment. If you see a sliver of the chamber viewed from the barrels end thru the forcing cone... i.e. a Slivery Moon then that could be your problem. Or Tell me what the Trigger feels like compared to the Uberti. If it's heavier, gritty, or a long pull that may be the problem also.
Good luck ... the Pietta are real good shooteres and very accurate from what I have expirianced.

[Omnivore]

If it's a trigger issue, here's how I dealt with mine;
http://thehighroad.us/showthread.php?t=417063

It's unconventional, but it works, it's adjustable, reversable, and it's functioned flawlessly to date.

[Omnivore]

I'm just now looking at a new Dixie Gun Works catalog. In it they list barrel groove and chamber diameters for Colt and Remington replica, Pietta and Uberti ".44" percussion guns. The Uberti Remington is given a chamber diameter of .450" and a barrel groove diameter of .460". A Pietta Colt 1860 Army is given a chamber diameter of .447" and a barrel groove diameter of .452".

If true, this means both revolvers have a barrel groove diameter substantially larger than the chamber. The Uberti would have the larger discrepancy of .010" with the Pietta barrel groove/chamber difference being only .005".

In the same catalog, a Euro Arms Rogers and Spencer .44 revolver is given a chamber diameter of .449" and a bore groove diameter of .448", more like a modern setup. A Pietta-made Starr Arms DA 1858 Army is said to have a chamber of .447" and a bore groove dia. of .450"-- a smaller difference of only .003".

So right there we're looking at percussion revolvers with chambers larger than the bore, or anywhere from 3 to 10 thousandths smaller than the bore, depending make and model.

I'm stumped. Are most of these lawyer-designed guns, or is there some real reason for this?

I should also point out that on the cylinder face of my Pietta Remington, there was some flowing of the steel, outward from the proof stamp, that distorted the mouth of at least one chamber significantly. I might never have noticed this if I hadn't chamfered the chamber mouths by hand, looking very closely there. The spare cylinder I'd ordered separately had no proof marks, and so the chamber mouths were pristine.

[72coupe]

Interesting post Omnivore. I think I will check my Remington and my Uberti Dragoon. If I reamed them out they would hold more powder.

But how do you refinish the freshly reamed chambers?

[Omnivore]

I now believe that the .460" barrel groove diameter spec for Uberti in the Dixie catalog is a misprint. Other places, they give a figure of .450" for the Uberti bores, same as the chambers. That would make more sense and would be in line with what others have been saying.

I'd consider not bothering to reblue the chambers. Next option; I'd go with the Birchwood Casey PermaBlue Gel, or paste - not the liquid, which sucks. I've used both a lot. The gel does a very nice job. Clean, degrease, rub it in a while, and rinse thoroughly. It's the closest thing to a professional hot blue I've seen yet, and it doesn't rub off like the finish produced by the liquid garbage.

Also; I don't think the difference in powder capacity would be much - you're only talking a few thousandths, but others have mentioned it as increasing capacity. Still and all; you can get up to a bit over 40 grains with a round ball into the Pietta Remington chamber as it is, and that's quite a bit. If you need more, go with the Dragoon. That's what they're made for.

[Hellgate]

I have two Navy .44s that are very light weight. One has reamed chambers (.450) and the other not. When shooting them side by side, the reamed gun kicks a little more. I'm assuming a bit more bore contact and swaging at the forcing cone. Trap shooters now use guns with a very tapered forcing cone that cuts down on recoil that would be noticed during a long day's shooting.