Teach Me

[sjs]

I was happily shooting and then cleaning my new 617-6 the last few days and a question came to mind that I have not heard discussed before. So, I spent a little time with the search function here, and also on google, and still did not find anything. Probably because I am counting angels on the head of a pin.

I am not technically inclined, but it seems to me the bore, the cylinder throats and the cylinder chambers on a revolver are all slightly different diameters. With a .22 the size is so small, the difference in diameters is even smaller than with larger calibers. I have always used a standard bore brush to clean the bore and the cylinder chambers and throats. It seems to me if the brush is small enough to fit the bore without damaging it, it will be too small to do a good job with the chambers, and something that fits the chambers just right will be too large for the bore.

This is not a practical problem because I seem to get my chambers clean anyway. But in theory, what would be the perfect tool or tools to clean these perfectly?

And, just what are those specifications for a .22 bore, chamber and cylinder throat?

And, if I wanted to get really obsessive about it (and I do) where could I find three different brush sizes for my 22 revolver?

For some reason none of this bothers me with my centerfire revolvers.

 

[diyj98]

I've often used a slightly larger brush or worn larger brush for cylinders. You might be able to use a .25 caliber brush on your cylinders or a worn .32 brush.

 

[Protocall_Design]

A .25 caliber brush is a good choice for chamber cleaning. For centerfires there are special chamber brushes that are larger for the same caliber than barrel brushes. An easy solution is to get one bore snake for chamber and barrel.

 

[ReloadforFun]

While I have not measured the diameter of a bore brush, they have always felt larger than the cylinder/bore when in use. They flex when pushed through the chamber/bore.

It's generally recommended to not reverse the direction of a brush in the bore, but toi push it all the way through before reversing. This prevents damaging the brush wires due to trying to leverage bring the larger than bore diameter wires in an unyielding situation.

 

[robertrwalsh]

I often use slightly oversize bore brushes for cylinder cleaning, i.e. .25 for a .22 bore. It is hard on the brushes but they are not that expensive to replace and it works well.

 

[2152hq]

"....And, just what are those specifications for a .22 bore, chamber and cylinder throat?...."

If you look at the SAAMI spec for a .22lr (Sporting) chambering, you can see that the chamber itself is not a straight cylinder. But instead slightly tapered from back to front. Very slightly,,from .230+ at the rear dia to .227d at the front.
Then a short 5* throat of just less than .040 in length that leads into.
the bore itself w/a groove dia of .222.

Bbls and cyl bore and chamber specs differ from gun to gun and mfg to mfg, but that is the spec they try to maintain.

A Match Chamber will have that chamber taper slightly less along with the dia's tighter. The headspace cut tighter along with the throat being shorter and of less taper depending on the ammo specified for use, etc.
But the overall idea is the same.

So looking at all of the diameters involved, starting at .230d at the base of the chamber and working thru the length of the LR chamber to .227 at the mouth, then thru the very short throat reduces to .222 dia to match that of the bore.

.008" difference , or to put it another way it's .004" on a side.

Any decent .22cal bristle bore brush that isn't damaged by careless use
(like reversing direction while still in the bore/chamber) will easily cover that 'wide range' of difference in internal diameters.

Don't over think stuff like this. Sounds like you are just doing a simple after shooting cleaning and oiling.


https://saami.org/wp-content/uploads/2022/08/ANSI-SAAMI-Z299.1-Rimfire-2018-Approved-2018-06-13.pdf

Scroll down to page 22 for the .22LR Sporting chamber specs, The Match chamber is also listed along with it.

 

[sjs]

Wow, great stuff 2152hq.

 

[Shotguncoach]

Here's a graph that I made of the chamber diameters at different depths of a K-22 cylinder when I went waaay overboard measuring things during my first experience with rimfire chamber reaming.

As others have mentioned, I use a .25 caliber brush for cleaning rimfire chambers.