Cap & ball conversion cylinder PRESSURE max. Not fps max

[nelsonted1]

I have a conversion cylinder for an 1858 Remington coming. THere is a limit of 850 fps- cowboy loads- with conversion cylinders.
I looked in my lyman cast bullet handbook and some of the loads are pretty high pressure with low velocity for instance 270 grain rcbs with max load of trail boss 718 velocity with 13,900 P.S.I.
Isn't pressure the problem rather than velocity? I know there has to be an easy to understand cut off for the limit for loads as a way to safely use the cylinders but I am wondering how does one figure out pressure? Or is it not important?

Ted

This isn't important to my situation since I have injuries restricting any kind of even medium loads, I am just wondering about it.

[mooman76]

Yes pressure is the problem but do you have a way of measuring it? No, and neither does anyone else outside a laboratory. But you can possibly measure velocity and that will get you in the ball park or at least as close as the average person can get.

[kaiser]

I have one in a Pietta 1858 that shoots 255gr and 230gr bullets very well indeed. While I have a 45-270 mold, I have not tried that bullet because of the limited COAL of its fairly short cylinder. If the loaded cartridge cylinder length is exceeded, it can "tie up" (read lock-up) the cylinder in most conversions if one of the bullets are not firmly crimped. I too have had good luck with Trail Boss powder with their recommended loads and have adhered to the advice of only using cast lead loads. BTW, my conversion cylinder was provided by Taylor, and I did not need to "fit" it to my frame to work; however, some users report minor adjustments sometimes have to be made.

[Outpost75]

The Lyman Cast Bullet Handbook 4th Edition (2010) has pressure-tested loading data in most of the Cowboy calibers.

The sights on the various Italian 1858 Remington reproductions are approximate for use with round ball and black powder loads, so using heavier bullets the revolver will shoot high.

The .45 Schofield data for smokeless cowboy loads on pages 282-283 does not exceed 13,000 cup and is in the correct pressure range for the cartridge conversion cylinders.

On p. 284-285 of the same volume you may use .45 Colt smokeless data in which the listed chamber pressure does not exceed 13,000 cup. Many of the "starting" load charges listed for the lighter 160-200 grain bullets are below 10,000 cup and would more likely shoot closer to the fixed sights on your Remington. Trail Boss is very suitable for such loads.

[nelsonted1]

The Lyman Cast Bullet Handbook 4th Edition (2010) has pressure-tested loading data in most of the Cowboy calibers.

The sights on the various Italian 1858 Remington reproductions are approximate for use with round ball and black powder loads, so using heavier bullets the revolver will shoot high.

The .45 Schofield data for smokeless cowboy loads on pages 282-283 does not exceed 13,000 cup and is in the correct pressure range for the cartridge conversion cylinders.

On p. 284-285 of the same volume you may use .45 Colt smokeless data in which the listed chamber pressure does not exceed 13,000 cup. Many of the "starting" load charges listed for the lighter 160-200 grain bullets are below 10,000 cup and would more likely shoot closer to the fixed sights on your Remington. Trail Boss is very suitable for such loads.
Outpost. Thank you!


On p. 284-285 of the same volume you may use .45 Colt smokeless data in which the listed chamber pressure does not exceed 13,000 cup. Many of the "starting" load charges listed for the lighter 160-200 grain bullets are below 10,000 cup and would more likely shoot closer to the fixed sights on your Remington. Trail Boss is very suitable for such loads.

[shortlegs]

Mine shoots 3" high and 3" left with the 255 gr lee boolit. 200 gr swc shoots closer to aim point but has to be seated deeply in the case to fit the cylinder length. I just bought a lee 160 RF to try. It looks like the 255, just shorter and lighter.