Old Navy Arms 1851 never fired much/at all?

[BCRider]

Old Armi San Paolo 1851 never fired much/at all?

So for this past weekend's shoot at my club's Winter Rendezvous I elected to shoot my 1851 .44cal revolver for the hand gun event. Well, apparently I have not taken this gun out before and shot it during the whole 3'ish years that I've owned it. Here's why.....

The chambers were horrendously tight even trying to load it with .454 size round ball. I mean tight to where the balls were swaged down onto the powder and the exposed nose of the ball was imprinted with pretty much a complete copy of the rammer's nose. Yet there was no cut off rings of lead.

Oddly enough the gun shot well. I knew it wasn't right but I kept going so I could finish off the course of fire. Luckily the balls were soft enough that I needed heavy but overly undue pressure to seat them They were just radically deformed to accomplish this though.

And at least there were only 16 rounds needed for the pistol part of the trail.

Anyway, after I got the gun cleaned up I measured the chamber mouths. First off it was clear that the mouths are tapered in over the first 0.1". That explained the lack of a cut off ring of lead. Second was the size of the seating portion of the chamber which was 0.438".

Checking my other .44 revolvers that accept .457 size balls nicely while producing a nice shaved ring I found that the chambers are .448".

So between the taper swaging the ball down in size instead of shearing off the metal and having to swage them down aggressively by an additional .010" its no wonder the poor balls were so deformed as a result.

Looks like I'll be buying a suitable reamer pretty soon..... I'll likely take this chance to see if the chambers all time correctly to the bore. This would also be the time to bore them out to slightly alter the centering of any which need it if there's any significant issues.

 

[Fingers McGee]

I'm guessing your .44 cal 1851 is a Pietta. If so, I'm not surprised you wee having a tough time seating the balls. IME, Piettas are built for .451 rbs, Ubertis for .454s, and ROAs for .457s.

 

[whughett]

My Navy Arms, circa 1964 has chambers that have a pronounced bevel around the mouths. Its a 36 caliber. The bevels are very uniform so assume it was factory. It is the only revolver of the nine I own that has that feature.

PS: It is a Ubertia. Not sure if Navy Arms had other manufactures or not..

 

[BCRider]

The flare or taper just at the mouth is very nicely done. So like you I'm sure that this flared mouth design was deliberate. It's the small size of the rear portion that I have the issue with.

The obvious solution is to slug the barrel before I go much farther. Then base what I'll do for either different size balls or reaming the chambers from what I find for bore and groove diameters.

I'm not keen on trying to stock another size of ball though. It's a lovely looking gun in great shape. The plan was to keep it as a sort of spare or alternate in case one of my 1860 replicas were to go south on me during a cowboy action match. But to allow a seamless transition I'd want to be shooting the same size ball for all the guns. So if this gun needs a really different size such as .451 then I'll likely be putting it up for sale.

I'll be slugging the barrel a bit later today and I'll get back here with the results.

 

[NineMilePete]

I wasn't aware that Pietta flared the chamber mouths. My 1858 Euroarms vintage 71 has flared chamber mouths. Another 1860 Euro, previously owned also had flared chamber mouths. Anyway, I like this feature.

 

[BCRider]

Pete, so far only whughett's Uberti is noted as having flared chamber mouths. My gun upon second checking it today has NO NAME! Without my reading glasses on the other day I saw "NAVY MODEL" and "NAVY ARMS".

EDIT- OK, I'm officially losing it! I went down after posting this and looking online for maker's marks and looking more at the barrel in big letters along the top is "ARMI SAN PAOLO-BESCIA-ITALY". Colour me deeply embarrassed....

I'd have to work with the helpful folks here to use the stamped proof and production marks to identify the actual factory. And that means serious macro photos which will come soon.

In the meantime a closer look at the chamber and bore sizes from slugging the barrel have these results.

Groove diameter of the bore is .4480 to .4485 depending on which groove lands I measure across on the slug. Bore diameter is .440 near as I can make out getting the fingers of my calipers down into the grooves on the slug.

Checking the chambers again I apparently let my mind run amok between the basement and the keyboard. The chambers are checking out at .441 to .4415'ish on the calipers.

The big difference in size from the chamber size to the bore's groove diameter certainly suggests that reaming is in order. So I'm going to go ahead and look at reaming out to the same .448 as I found on my other .44's. This should make the gun more easily useable with .454 to .457 round ball like I can use with the other guns.

By rights it should also give a little boost to the acceptable accuracy it already has by letting the balls engrave more distinctly on the rifling.

More news on what is turning into a project as it occurs.