View Full Version : How hot to load a conversion?

July 9, 2010, 06:17 PM
I've been thinking that at some point I'd like to get a conversion cylinder or even better a converted pistol in such as a '60 or a '58. My question is how hot can you load a 45 colt conversion? Cowboy only or can I go up to original specs of about 250/255gr at about 900/1000 fps? I really wouldn't be too interested if I have to stick with cowboy only loads.

July 9, 2010, 06:22 PM
You can go up to original specs.

Gaucho Gringo
July 9, 2010, 07:33 PM
I will agree with Hawg. When they were building and using conversions there were no "cowboy loads" They were using the same cartridges that were sold for the other .45 LC cartridge revolvers at the time. Today's normal .45 LC loads approximate the loadings of the 1870's-early1900's. The steel used in today's conversion guns is better than the originals. Just don't go and try to fire Ruger or FA loads in them.

July 9, 2010, 07:53 PM
Thats real nice to know. Thanks guys!

Jim Watson
July 9, 2010, 08:45 PM
I agree that modern steel in cartridge conversion repros or cartridge conversion units will stand the pressure of full charge (but not +P) loads.
But how will the old open top frames hold up? Well enough if that was all you had to defend the house, but I would expect them to shake loose sooner with full charges. I would expect a Remington conversion to be sturdier than a Colt type.

By the way G.G., the .45 Colt was not used in 19th century cartridge conversions. The .38 and .44 Colt and .44 and .46 Remington were lighter loads.

July 10, 2010, 05:43 AM
I disagree.:eek:

You really need to talk to the cylinder manufacturer.

R&D recommends..

"These cartridge converters are designed to convert your reproduction percussion revolvers to fire Black Powder Cartridge & Cowboy ammunition"

This conversion cylinder is for BLACK POWDER cartridges or black powder equivalent cartridges (also called Cowboy Ammunition) on a steel frame ONLY. Attempting to use modern ammunition will create a dangerous condition that can result in injury or death."

From Kirst.

"All Kirst Cartridge Konverters™ are precision CNC machined in the USA from 4140 Steel and heat-treated. The cartridge conversions are rated "For Black Powder or equivalent loads only," which includes the current Cowboy Loads on the market."

A conversion cylinder in a open top may cause frame cracking at the trigger and bolt screw holes. This was a problem with the originals using black powder only.

Pushing a 250/255gr at about 900/1000 fps is a pretty stout load. I would not do it in a conversion cylinder.

July 10, 2010, 06:22 AM
I will defer to MCB's knowledge.

July 10, 2010, 07:32 AM
Hawg, I'm just repeating what's on the conversion cylinders manufacturers web page. I have zero first hand experience.

I would think a 4140 cylinder in a steel frame Remington would probably handle standard .45lc with out coming apart. It may stretch the frame after ??? loads. I would not shoot a standard .45lc in a open top. I don't think it would be a catastrophic failure but I do think it make crack or bend the frame in short order.

I've come close to buying a conversion cylinder a few times but the BP only or CB loads is just to limiting. I do load BP for my SA Rugers, that scratches the itch. I love my BP but a full house .44mag is something to experience in a SA revolver. A hot rod .45lc is pretty impressive too.


July 10, 2010, 08:37 AM
Did some checking around on other forums and a few people have contacted Uberti and Taylors. According to them the Uberti factory conversions will handle factory loads but not +P including the Colt open tops.

July 10, 2010, 12:02 PM
That is probably correct, I recall reading something about a different heat treat on the purpose built conversion from Uberti. That is one revolver I keep looking at and drooling.

July 10, 2010, 01:33 PM
I know someone who just bought a NIB Ruger OA, a stainless R&D 6 shot .45LC conversion cylinder and some UltraMax .45LC ammo with 250 grain RNFP lead bullets. The box of ammo does not say that it's cowboy ammo anywhere on it but the UltraMax web site shows that it is with a velocity of 725 FPS.
After firing it for the 1st time he sent me a photo of the target to show how well it shot. I realize that every ammo and gun is different but this UltraMax ammo shoots and works well.


July 11, 2010, 03:15 AM
Arcticap I can attest to them Ultramax Cowboy ammo loads work very well and are accurate. Have tried them in my Rogers&Spencer and ROAs .45Colt good stuff...fired w/ R&D 6 shot cylinders.

July 11, 2010, 08:59 AM
This is a subject near to my heart. I do not understand why someone would wish to buy an 1860s style gun with 1860s engineering, then buy a conversion cylinder made to 1860s specs (with admittedly better steel) and expect to shoot hot loads.
The design of the guns does not lend itself to the battering that hot loads will create.
For the same expense, indicated in the gun above with conversion cylinder, you can buy a Ruger, in your choice of calibers, that will handle almost anything you want to throw at it. And do a better job than the conversion.

July 11, 2010, 09:48 AM
I agree 100% NOZ. I love conversions. I own one and want to own more someday. These gun designs are 140 years old and made for 140 year old ammunition loads. Full load BP cartridges. That's it, unless you want light target smokless rounds. They are not made for hot, modern self defensive loads. BUT... the original poster asked if you could go up to original specs. That would be full load BP cartridge. I would say yes you could.

July 13, 2010, 01:01 AM
Regarding the firing of 200 grain jacketed CCI Blazer ammo at 1000 FPS from the SS Ruger Old Army with R&D .45LC conversion cylinder, shooter Bob wrote:

My friend had 3 rounds left in a box of Blazer ammo, I went to Blazer ammunition reference chart to see about the ammo.

200 gr JHP
Test barrel....71/4''
Velocity....Muzzle.....1,000..... FPS.
50 yds.....935...FPS
Energy, ft-lbs......50yds...388 ft-lbs
Trajectory..(25 yd sight in). inches........25yds is 0........50yds is -1.4 inches

Pictures of my target, I have the ROA sighted in with the Ultramax 250 gr cowboy ammo. I did not move my sights, I'm going to have to buy a box of Blazer ammo. R&D conversion specifications 750 to 850 fps. After shooting the 3 rounds of Blazer ammo I looked the conversion and ROA over good and checked the empty cases for problems. Good to go :)...After I get done playing with the R&D, I will start with the black powder ( I love this gun )

July 19, 2010, 08:28 PM
period. the cowboy load is considered antique by Atf and thus the low powered designation is a catch 22 .saami standards apply,born a black powder,always a black powder,drop in conversions are legal as drop in replacement parts, the manufacturers arent nuts,they want thier product safe,also some converters use 45 acp and the pressure is 22,000 psi hot compared to 45 lc @14,000 psi same steele krists are heat treated 4140crome moly alloy strong stuff! does hornady have a light mag for 45 lc?hhhhhhhhmmmmmmmmmmmmmmmmmmmmmmm......................:cool::cool:

July 20, 2010, 10:24 AM
Just a thought, I shoot hot loads thru a 137 year old designed revolver and haven't blown anything up yet.

I don't own a conversion, but wouldn't feel unsafe shooting saami pressure rated ammo thru one. After watching some you tube stuff, I'm pretty sure most of the howdy doody crowd shoot near squib loads out of theirs and while they may wear mechanically from lotsa rounds fired I dont think that bunch is going to suffer over pressure problems.

Has anyone, or know anyone, who has had a catastrophic failure?

July 21, 2010, 08:41 AM
I'm not asking about a hot 'Ruger Only" load. Just orignial specs. [email protected] If this load is safe with BP would it also be safe with smokeless, would the pressure be the same?

July 21, 2010, 11:08 AM
Just because the velocity is the same doesn't mean that the pressure when loaded with smokeless is the same. It all depends on which smokeless powder is being loaded.
However, just because the pressure is greater doesn't mean that it must be unsafe for the cylinder or the gun either.
Even if the cylinder is totally safe that doesn't mean that it's not going to be harmful to the frame or lock up parts.
It could be perfectly okay for the gun but who knows how long it will last without a problem being caused by it?
The powder or load isn't being specified, the type and model of gun isn't being specified and every gun could be different.
Generally it works, but no one wants to recommend to exceed the manufacturer's recommendations without a disclaimer.
The guns and cylinders are designed to have a margin of safety built into them. Chances are that most loads will probably work just fine. Make sure not to use a brass frame gun. If your Italian gun gets battered or becomes loose after a while then that's what can be expected to possibly happen. That doesn't mean that it will or that it won't. One person's load in their gun may work fine, and another person's load in another gun may have some consequences after a while.
No one really knows how many rounds a gun will last before something changes and may need attention or repair.
I'm not sure that there's any easy answers.
Do it with caution until you notice a problem that needs to be fixed.
Everyone tests their own individual revolvers the way that they are set up, loaded and fired. Not every gun and load are equal. Generally there's not many accidents or significant problems being reported. But what anyone does is at their own risk.

July 21, 2010, 01:27 PM

I have experience with Kirst 45Colt conversion in various Remington 1858 ( Pietta and Uberti, short and standard barrel) and various Colt 1860 and 1851 (Pietta, short and standard barrels).

The Rems can be loaded with any standard 45Colt (but not P+) whatever smokeless or BP (full load) with 255grs bullets ; They stand it without any problem (although a mate with a Uberti seems to have noted an increase of the gap cylinder/barrel) . I just recommend that you check regularly the cylinder/barrel gap.

The open-top (Colt 1860 and 1851 ) are another story : one or two cylinders with the above loads and the wedge gets battered and the cylinder/barrel gap notably widened. The wedge is soft metal and act as a fuse that avoid other damages. The wedge can easily be formed back to original shape once or twice but obviously this pattern is less resistant and softer loads have to be used. Hence I would recommend lighter bullets, i.e. 200grs . By the way, the conversion is noted 45Schofield evenso it is possible to load 45Colt............

The wedge is a perfect witness of the adequacy of the loads : it should not be battered.

Maybe the converted opentops marketed by Uberti have better steel heat treatment than cap§balls but I doubt they would stand standard 45Colt on the long run......

To make things easier, I load standard 45Colt 255grs for the rems and 45 Schofields 200grs for the Colts 1860/1851

Have fun

August 16, 2010, 12:58 AM
no way are you gonna hurt a krist konveerter,with standard pressure ammo .:cool:try 7.5 grains bullseye cci 300 primer with a 255 grain hornady cowboy @936 fps :cool: