polishing chambers?

[bushka]

at what grit does one stop to acheive mirror chambers?
need to know when I buy a flex-hone.
thanks
B

[leftiye]

600 is fine enough. 1200 to 1500 for closer to true polishing. There is a company that makes abrasive bristled brushes that are just the ticket for chambers. Check with MSC, they carry them. From about 1/8" up to large enough to finish engine cylinders, in various grits. Kinda pricey.

[mister gizmo]

Flex Hone is what you're talking about. 600 grit will do the job. Small flap wheels are almost as good. Don't be seduced by valve grinding compound.

[Shotgun Luckey]

Is that what I want to do so my 38 special brass will FALL out of the cylinder after firing?

[JIMinPHX]

My final polishing is done with lead-away cloth. That stuff has a very fine abrasive that will leave an absolute mirror finish.

[Newtire]

My question is that if the cylinders are too shiny, will that be detrimental in not letting the cases grip the cylinder bores and thereby put less pressure on the frame of the revolver? I might want to give that a try in my Ruger if it's safe...

[chickenstripe]

Contrary to popular belief. No case should grip the cylinder or chamber. The rear of the firearm (bolt or reciever) is designed to accomodate the full force of the load.

[felix]

WRONG! Without grip, all gas from the powder burn will excape backwards. ... felix

[felix]

To answer the other question, too shiny or too rough a container is hard to determine in advance. Sometimes a super smooth cylinder/chamber will grab the case just perfectly, other times not so. It seems to boil down to how much/quality lube is between the case and the chamber, or how close the case fits in the first place, when assuming a certain load pressure. It won't hurt to polish the chambers, but lower the pressure to compensate. The chrono will tell you the difference between the before and after polishing. ... felix

[leftiye]

We should here remember that many revolters have shiny chambers with no ill effect. Conversely, while it could be hard to make these shiny chambers more shiny, it serves no purpose, and a nice smooth surface is all that is really beneficial to extraction. Mirror polish probly won't hurt anything, and probly won't help anything either. Rough chambers that press machine marks into the brass could use a little help (ya think?).

[chickenstripe]

As I had stated previously, it is contrary to popular belief.

"Sealing the gasses" and "gripping the chamber" are different.

Here's a bit of research into action and casing design intent.

http://www.varmintal.com/a243z.htm

Or a quote from the study that sums it up fairly well:
"Trying to use the weaker brass to lighten the load on the action and bolt face of a rifle by having the brass grip the chamber is analogous to using a car's radiator to protect the bumper in a front-end collision. A polished chamber minimizes case stretching, reduces case head separation, and increases case life."