Brass Frames and Conversion Cylinder

[rommel]

I know very little about cylinder conversions to shoot cas loads, so when asked this question yesterday at the firing range I was stumped.
If cartridges shoot the same equivalent of black powder as a regular cylinder in a cap and ball, how is it that brass frame revolvers are not strong enough to handle a cartridge conversion like steele frame revolvers.
I have never shot CAS loads, so i must plead ignorance to differences between them and standard black powder.

[filmokentucky]

For one thing, some of these guns are barely adequate for use with loose powder and ball. It is always better to be safe than sorry. And no manufacturer of conversion cylinders warrants them for use with brass frames, so if something goes awry you are on your own, perhaps minus a a revolver. And some fingers.  And maybe part of your face.                    Most of the conversions are made for Uberti and Pietta revolvers, so you may not be able to get a conversion for your gun anyway.

[Will52100]

the powder may be the same or even less, but the bullet weight is most often higher and helps create more pressure, plus it's more of a legal issue than anything else as long as you use low pressure stuff, but if you stick high pressure loads in it and it blows up in your face your own your own.  Not to mention if you stick the conversion cylinder in a brass frame that has shot loose, which happens a lot.  The steel frame will handle a lot higher pressure loads, thus a higher safty margin.

[Flint]

Will and Filmokentucky basically said it.  The typical cartridge bullet is up to twice as heavy as a round ball, also usually harder lead.  The cartridge is much more efficient than loose powder and ball, and generates more pressure.  The bullet slamming into the forcing cone is trying to pull the cylinder pin out of the gun, and eventually will.  A brass frame just amplifies all the weaknesses of the open top design, and even in the Remington design will stretch a brass frame.  The brass or bronze frame was a wartime emergency solution for the Confederacy's arms shortage.  Bronze gunmetal was only used otherwise in very small low powered pocket pistols.

When Winchester chambered the 44-40 WCF cartridge, they went back to iron for the frame in the 1873 model.  The newly made repro Henrys and 66s are made of a much stronger bronze than was available a century ago, and can stand the "Cowboy" loads we use in CAS.

One thing I noticed was how poorly Pyrodex works in a muzzle loader compared to real black powder (The pellets work better), but it seems to work very well in cartridges.  Black powder also seems to shoot cleaner and better in a cartridge.  I believe it is the better compression and hard crimp on a heavier bullet in the cartridge, also lacking is the gas leak through the nipple.

[xnmr53]

rommel,

Keep this in mind. The orignal design for the percussion revolvers called for steel frames, not brass, and this was strictly an emergency measure by the Confederates, on the assumption that the carrier would replace it with a good, steel Yankee revolver at the first opportunity.  :mrgreen:

[unspellable]

"Tain't the pressure so much.  It's the cylinder recoiling and hitting the brass frame.  Gradually beats it to death.