Picked up a 51 Navy from Cabella's today after looking for a used gun for about a decade.

[M. De Land]

I've been looking at all the gun shows for a beater 51 in .36 cal with a steel frame that I could over haul for about a decade. I've seen brass framed guns in .44 but apparently the steel framed Navies stay at home. Having a "C" note gift card in my wallet I had forgotten about I decided to pay the extortionate price they were asking and see how well the new Pietta's are put together. I did get a small discount for being a veteran and for taking the display model with a few dents and scratches but I have to say upon getting it home and torn down and spec-ed out I am very pleased with the quality of fitting they have stepped up to.
Here are the specs I measured for those who are interested in such stuff.
1.Cylinder/barrel gap- .003
2.bore diameter plug gauged - .357
3.groove diameter Powley gauge checked - .371-2
4. Land and Groove count - 7
5. pitch - 1 in 24 best I could tell
6. individual groove depth .007
7. Chamber mouth diameter plug gauge checked - .366
8. Factory trigger pull 2.75 lbs , clean breaking
9. Arbor end fit is tight with minimal wedge depth set just inside the hook latch.

Here is a shot of the cylinder face that could have been dressed out better. The chamber mouths are heavily chamfered which I had not seen before and hope they don't spit badly.
The bore slug was driven and retrieved so as to measure the groove diameter in the uneven grooved count barrel. One needs a Tri-Mic or a Powley gauge to accurately measure odd count rifling.
She has a few handling dings and scratches but it will have a lot more before I'm done shooting it
The plug gauge shows a very even bore and round cylinder mouths !
Bore cylinder alignment is excellent also checked with plug gauges which is one of the main ingredients to accuracy.
Last three pictures are checking alignment with a plug gauge and cleaning rod for depth indication. All chamber alignment checks were done with gravity simply tipping the muzzle up and letting the gauge slide into the chamber and then checking depth with the cleaning rod.
Click on picture to enlarge.

 

[TDM]

Hard to beat an 1851. Congratulations!

 

[M. De Land]

Hard to beat an 1851. Congratulations!

I'll shoot her for a while over sand bags but expect I may have to open up the chamber mouths to groove diameter to get her best accuracy.
I stripped her down today and got here cleaned up and re-lubed. I also uses a needle nosed diamond file to break the edges on both side edges of the bolt dome and take the corners off the pin notch/slot in the hammer face so she won't suck caps.
I'll get some slick-shot nipples coming for her as well.
I expect I'll probably cut a dovetail and make a new front sight for it eventually if the POI needs adjusting.
The cylinder locks up "Tighter en Dick's hat band" which is a good deal and the timing is very well adjusted although I prefer a bit early bolt drop in any revolver which is the main reason for dressed bolt dome edges.

 

[TDM]

I have a Pietta 1851 too, it’s a good shooter.

 

[M. De Land]

I have a Pietta 1851 too, it’s a good shooter.

I capped the cylinder and fired all six with no problem and no cap sucking. I will need to open the nipple wells in the cylinder a bit so the cappers will fit down over the nipples better.
I'm going to re-contour the trigger profile as well as I like them much closer to the rear of the trigger guard bow. It'll need to be heated and bent to the desired profile and then probably re-hardened. I'll use heat control paste on the sear area so it may not need to be re heat treated but time will tell.

 

[Wheelman]

Thanks for posting this. Looks like a nice addition.
Congrats!

 

[M. De Land]

I capped the cylinder and fired all six with no problem and no cap sucking. I will need to open the nipple wells in the cylinder a bit so the cappers will fit down over the nipples better.
I'm going to re-contour the trigger profile as well as I like them much closer to the rear of the trigger guard bow. It'll need to be heated and bent to the desired profile and then probably re-hardened. I'll use heat control paste on the sear area so it may not need to be re heat treated but time will tell.

I spent the PM forging back, profile filing and sanding out the trigger to fit the bow better and give more space for large fingers. This feels much better to me and with the added benefit of limiting over travel after braking the shot.
The photos show new trigger position at rest, half cock and full cock. It moves the trigger rearward close to 3/8's of an inch from what the factory offers.
The trigger now fits the profile of the bow much better.

 

[45D]

Looks nice! I like an over travel stop. I install an " in the frame " adjustable one on request. I like the looks of a close travel trigger though, reminds me of a Colt Bisely.

Mike

 

[M. De Land]

Looks nice! I like an over travel stop. I install an " in the frame " adjustable one on request. I like the looks of a close travel trigger though, reminds me of a Colt Bisely.

Mike

Mike, do you know the reason most of these imports have such a difference (smaller diameter) in chamber mouth to groove diameters ? I imagine the original Colts were the same but I've never checked to see.
They would have been counting on ball or bullet bump up but why do that rather than fit chamber mouth to groove diameter to begin with ?
I got the trigger re-profile idea from my Ruger Bisely. I can't think of any hand gun grip and bow shape I like better both from looks and feel than what Ruger came up with. I'm guessing Ruger got that from Kieths # 5 Colt alteration.

 

[45D]

Mike, do you know the reason most of these imports have such a difference (smaller diameter) in chamber mouth to groove diameters ? I imagine the original Colts were the same but I've never checked to see.
They would have been counting on ball or bullet bump up but why do that rather than fit chamber mouth to groove diameter to begin with ?
I got the trigger re-profile idea from my Ruger Bisely. I can't think of any hand gun grip and bow shape I like better both from looks and feel than what Ruger came up with. I'm guessing Ruger got that from Kieths # 5 Colt alteration.

No sir, not really but I think it's probably their "safety valve " ( lawer protection). How can you "have an incident" if the ball/bullet is smaller than the bore? I think obturation "played into their hands" accidentally and they have just kept it that way. I always see posts about how much better accuracy gets when it's the other way around ( folks getting chambers reamed). I've never checked that relationship
on an original but surely someone has. Fortunately the cylinders I use are of "unmentionable" specs so it's not a problem for me.


I agree, the #5 is probably where that came from.

Mike

 

[M. De Land]

No sir, not really but I think it's probably their "safety valve " ( lawer protection). How can you "have an incident" if the ball/bullet is smaller than the bore? I think obturation "played into their hands" accidentally and they have just kept it that way. I always see posts about how much better accuracy gets when it's the other way around ( folks getting chambers reamed). I've never checked that relationship
on an original but surely someone has. Fortunately the cylinders I use are of "unmentionable" specs so it's not a problem for me.


I agree, the #5 is probably where that came from.

Mike

I have found that lapping bores level and thus removing any tight spots, re-cutting the crown, forcing cones and reaming the chamber mouth to groove diameter has added accuracy with before and after testing but have never actually tested out the accuracy differential each procedure added or subtracted . The plan is to test just that one factor with this new gun.
The trouble with giving a gun the full treatment is one is not able to isolate what gave the most benefit and what was superfluous.

 

[nkbj]

I want to try chambers that in the front are at slightly over groove diameter and then have a short taper to slightly less than groove diameter, the taper being at the depth needed to engage the base of the bullets as they are swaged in. The top of the powder charge would be at the taper and get compressed by the bullet. That would provide the positive seal with displaced lead and create a slight bulge ahead of the taper. For round ball the forward portion being slightly over groove would be just right. This way the round ball shooting characteristics of revolvers could be improved and long bullets would have excellent alignment during loading. All that would be needed is to select the depth of reaming the chambers rather than reaming full depth.

 

[M. De Land]

I want to try chambers that in the front are at slightly over groove diameter and then have a short taper to slightly less than groove diameter, the taper being at the depth needed to engage the base of the bullets as they are swaged in. The top of the powder charge would be at the taper and get compressed by the bullet. That would provide the positive seal with displaced lead and create a slight bulge ahead of the taper. For round ball the forward portion being slightly over groove would be just right. This way the round ball shooting characteristics of revolvers could be improved and long bullets would have excellent alignment during loading. All that would be needed is to select the depth of reaming the chambers rather than reaming full depth.

One does not want to full depth ream rebated cylinders in any case. Even in non-rebated cylinders usually only the front portion is reamed unless your after a larger powder capacity.

 

[Scott Jones]

I recently picked up a fancy engraved Pieta 1851 with white grips from Midway; it was on sale. The grips were way oversized, took about two hours of filing/scraping/buffing to get them to fit the frame. When I shot it, it shot to point of aim, the only Colt clone I have ever shot that did so, and it was reasonably accurate. I did open up the sighting notch in the hammer, which I do with all my Colt clones.
As to the discussion about cylinder-bore diameters, my original 1851 measures .373 at the cylinder mouth, all 6, and the barrel at the breech .368. This 1851 has been "well used". My 1860, Army issue, measures .440 at the forcing cone, and the cylinder mouths vary considerably, from .350 to .440. It has also seen hard service. Can't afford any better ones. Haven't measured my 1849 or other C&B revolvers I have.

 

[M. De Land]

I'll shoot her for a while over sand bags but expect I may have to open up the chamber mouths to groove diameter to get her best accuracy.
I stripped her down today and got here cleaned up and re-lubed. I also uses a needle nosed diamond file to break the edges on both side edges of the bolt dome and take the corners off the pin notch/slot in the hammer face so she won't suck caps.
I'll get some slick-shot nipples coming for her as well.
I expect I'll probably cut a dovetail and make a new front sight for it eventually if the POI needs adjusting.
The cylinder locks up "Tighter en Dick's hat band" which is a good deal and the timing is very well adjusted although I prefer a bit early bolt drop in any revolver which is the main reason for dressed bolt dome edges.

Well It turns out it does have a bit of timing correction needed that I did not notice at first while cycling the action. The bolt is just a tad slow/late in being retracted fully before the cylinder begins to rotate evidenced by the little bright spot in the bluing on the back top of the bolt notch.
One method of correcting this is to shorten the hand a bit to retard cylinder rotation and the other is to make a tool steel collar that enlarges the hammer cam diameter so the bolt finger is in closer contact with it thus making it lift sooner. Hand shortening is limited because one may not have enough rotation left for full lock up but is much easier to do.
The tool steel cam collar works better but is harder to make, heat treat and install correctly. Of course one could just make a larger diameter cam and install it. Having done it both ways I think a collar works just as well but is about the same amount of labor as making and installing a new larger diameter cam.
Here is a photo of the late bolt lift not fully clearing the back side of the bolt notch when cylinder rotates.
Now that the action is smoothing up a bit I can feel it when retracting the hammer.

 

[M. De Land]

Well It turns out it does have a bit of timing correction needed that I did not notice at first while cycling the action. The bolt is just a tad slow/late in being retracted fully before the cylinder begins to rotate evidenced by the little bright spot in the bluing on the back top of the bolt notch.
One method of correcting this is to shorten the hand a bit to retard cylinder rotation and the other is to make a tool steel collar that enlarges the hammer cam diameter so the bolt finger is in closer contact with it thus making it lift sooner. Hand shortening is limited because one may not have enough rotation left for full lock up but is much easier to do.
The tool steel cam collar works better but is harder to make, heat treat and install correctly. Of course one could just make a larger diameter cam and install it. Having done it both ways I think a collar works just as well but is about the same amount of labor as making and installing a new larger diameter cam.
Here is a photo of the late bolt lift not fully clearing the back side of the bolt notch when cylinder rotates.
Now that the action is smoothing up a bit I can feel it when retracting the hammer.

I finally got around to correcting the bolt drag on the back of the cylinder notch. I had originally thought this was a late bolt lift timing issue but checking closer I noticed the bolt dome hand been ground poorly leaving it a bit high and miss shaped on the right top side.
I removed it and secured the bolt in my small machinist vice and took a thousands or two from the that area with a medium diamond file, smoothing the dome profile which was just enough to make it clear the back of the notch wall when retracted before cylinder rotation begins.
Hopefully you can see the corrected bolt dome profile from the end shot.
A bit of touch up blue reveals no more bolt drag contact on the back upper side of the bolt notch.
Another fitting issue noticed in the new gun was the pin fit in the lower lug was such that I could feel a bit of lateral/radial movement/play before the wedge was fully seated which I know was most certainly flexing when the gun is fired from bullet torque.
That was adjusted by expanding the end of the pins radially with a few strokes of a spring loaded prick punch and some trial and error fitting. All movement is gone now without any wedge influence to tighten it.
I'll see if I can get a couple of photos of both adjustments that may be of help to some one experiencing the same problems.
Click on the photo to enlarge.