I need some help!
does anyone have a vague idea, or better yet an accurate idea of what the pressure is when a flobert .22 cb cap is fired?

I assume you are asking about what is known today as the 22RF CB? The proof pressure would have depended on when the firearm was produced. The rimfire has been around for a long time. It has gone from black powder to semi-smokeless to the early nitro powders into today's smokeless powder. SAAMI does produce a document dedicated to the rimfire. http://www.saami.org/Publications.cfm

I can tell you that the American standard loading for the CB using black powder was a 30 grain conical ball, 2 grains of black powder with produced m.v. 650fps with a m.e. 28ft.lbs. The early American smokeless produced a mv 720fps with a m.e. 34ft.lbs.

The current SAAMI Maximum Average Pressure for the 22 LR, 22 Mag, 17 Mach 2 are loaded to 24,000 psi Maximum Average Pressure with the Piezo system. This is according to recent email from CCI.

Pete

I think you will find the pressures a lot lower on the flobert caps. Rottweil produced a short copper shell loaded with a round ball and propelled by priming compound only. They are relatively accurate because they are round balls. In North America, we have a CB cap which seems to be a .22 short shell with a light elongate bullet that is less accurate in my experience, in most rifles because of the bullet jump to the rifling. I think they are loaded with priming compound only.
I suspect that neither cartridge produces more than 5 or 6000 psi but have no data to back that up. The original bp loads must have been pretty low pressure judging by the cylinder thickness on many of the pistols chambered for it.

cheers Doug

The original American .22 was developed by S&W in 1857. It had a 30grn bullet with 4 grains of black powder. Today, we know this round as the 22 short. In 1878 the BB cap was introduced. It was round ball with no powder only the priming mixture. The CB (conical ball) was introduced in 1886. It was loaded as I stated above with 2 grains of black powder. The .22 rimfire CB is still available.

Pete

While we're on the topic of the modern 'CB' loads, don't forget the CCI loading marketed as 'CB Long' which is the short conical bullet in .22LR brass.
It's subsonic, and in every rifle I've shot it in - very accurate.
In my 9mm/.22 cape gun and my Anchutz it's silent, quieter than my .177 air rifles.

I can't say for sure what the propellant is or what the chamber pressure would be in any particular gun.
Perhaps a note to CCI would be in order to answer that kind of question.


--Tinker

About the term Flobert.

Louis Nicholas Flobert was a Paris gunsmith who was looking to develop a rifle that could be fired indoors for practice in 1845. He eventually developed a charge of 2 grains of black powder with a single Lyon No. 3/0 shot (.22 caliber). This was meant as a 25 foot target affair. Unfortunately, the wives were not amused with all the smoke that it generated. His solution, in 1847, was to use a percussion cap with only the shot. In 1855, he developed and patented an extractor for this self contained cartridge. Today we would refer to this as the .22 BB.

These guns were very popular. Many makers started to produce Flobert variations. Apparently while he held several patents, he never copyrighted his name. The variants were often chambered for .22 Long Rifle , .32 Rim Fire, 6mm, 9mm, etc. Remington even offered a Belgian made version.

RWS currently makes .22 Flobert BB & CB ammunition. http://www.22ammo.com/rws.html



Pete

I just pulled the slug on a Remington 22 CB long. Inside was 1 grain wt of a fine (tiny) round flake powder. It is probably only about 2 powder grains deep on the bottom of the shell. I didn't have any CB shorts around to pull apart.

cheers Doug