Colt 1851 Navy Conversion, shooting non BP rounds

[Native shooter]

I'm not sure if this is the right place to put this, but I was going to purchase a 1851 colt navy london model made by uberti. And I see that conversion kits with the gate and all the works, I read that there are BP rounds made in .38 special, but I was wondering does it have to be only BP rounds? Thinking that since it made with modern metal, wouldn't shooting non BP rounds work? Like the Uberti Colt cattleman can shoot both, so wouldn't a converted Colt Navy work too?

 

[Prairie Dawg]

Yes, the conversions are safe for loads in the "cowboy" pressure range.
No high pressure loads.
--Dawg

 

[Willie Sutton]

This has been asked to often that there ought to be a sticky thread for it.

You can shoot any SAAMI standard pressure cartridges in any of the conversions. They are "intended" for use with "plinking" pressure cartridges (as befits what we shoot these elderly designs for), which some folks call "Cowboy" loads. Truthfully though "real" Cowboy loads are loaded so weakly that they are well below the strength ratings of both the frame and cylinder of these conversions. If you restrict yourself to standard velocity cartridges loaded within SAAMI specs, you'll be fine. You will reduce long term wear by shooting reduced power loads *just like in any revolver*. And by "long term", I mean in the 1000 round increments, not the 10 round increments. If you want to stick a cylinder load of modern self defense cartridges into one for the your bedside, do so with confidence as long as you stick to standard (not +P) loads. I simply wouldn't make a long term habit of it.


Willie

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[Driftwood Johnson]

Howdy

If you are thinking of shooting a replica of a 36 caliber Colt Navy with cartridges, there is one thing you should be aware of. The bore size is wrong for modern 38 caliber cartridges. .357 bullets are too small for the rifling of a 36 caliber Navy replica. Most Navy replicas have a rifling groove diameter of .375. When the originals were converted to cartridges in the 19th Century, cartridges with heeled bullets were used. Heeled bullets are the same diameter as the outside of the cartridge case, unlike modern bullets which are the same diameter as the inside of the case. These 19th Century 38 caliber cartridges were designed specifically for the 36 caliber cartridge conversions. There was no chamber throat in these revolvers and the chambers were the same diameter as the rifling grooves. So true 38 caliber cartridges with heeled bullets worked in these guns.

The modern 'cartridge conversion' revolvers made from the ground up as cartridge guns by Uberti, such as their Open Top and Richards-Mason conversions have had their chamber and bore specifications upgraded to modern standards to accept modern 38 Special ammunition. But the 1851 Navy Cap & Ball replicas made by Uberti and Pieta still have the larger diameter chambers and rifling. Firing one of these with modern 38 Special ammunition requires either that the barrel be lined for 357 bullets, or that hollow based bullets be used which will expand at the base to engage the rifling. Firing regular .357 bullets in a Navy replica with a conversion cylinder will result in the bullet not engaging the rifling properly and accuracy will be poor. A good friend of mine has a pair of Uberti Navy revolvers that he shoots in CAS with conversion cylinders. The barrels were lined to accept modern 38 Special ammunition. Read the fine print on the specifications for the 1851 conversion cylinders sold by Taylors, Howell, and Kirst. They all mention this.

Of course, one might ask, why a '36' caliber revolver actually has rifling .375 in diameter. It is because the convention for naming calibers was different in Cap & Ball days. The hole drilled (or bored) in the barrel of these revolvers was about .360 in diameter. Then when the rifling was cut, the tool cutting the grooves cut them deeper. The caliber was called out as the bore diameter of .36, not the rifling groove diameter. It was just the naming convention of the time.

P.S. the other thing to remember is no brass frames with cartridge conversion cylinders. Steel frames only.