Rimfire chamber

jGEE

jGEE

Joe Golden
Before you guys start throwing things at me for a stupid question please let me explain:

CUTTING A RIMFIRE CHAMBER:
I can see how COMPLICATED it would be to cut a square CENTERFIRE chamber, i'm not at that skill level.

Cutting a RIMFIRE CHAMBER does not seem near as complicated. What little common sense I have it seems to me a piloted rimfire reamer would follow the bore centerline.

With just good common skills why wouldn't a piloted rimfire reamer follow the bore centerline? Your just removing the rifling and a few thousands to make the chamber. I center the barrel in a lathe and I put just the slightest amount of pressure on the back of the reamer with the centered tailstock. I then turn the barrel by hand one direction and turn the reamer by hand the other direction.

No I don't know how a multi fluted reamer cuts maybe there is something here. It seems to me unless you really really tried, How would you cut a rimfire chamber off center?

I know i'm missing something here maybe someone could point it out to me.- i'm only talking about rimfire here, thanks ... joe
 
RF and CF chambers are cut the same way in my shop. I only use bushed piloted HSS reamers, I run the lathe at 245 rpm, I advance the tailstock wheel with the reamer held in a floating reamer holder/chuck, I advance slowly and clean and re-oil often.
I don't know how to go about cuting an off center chamber!
 
According to Bill Calfee, he doesn't cut his match chambers on center. Has to do with the accumilation of residue after each shot. I think he even talked about it in one of his articles in precision shooting magazine.

This should stir the pot on here...lol

Hovis
 
By Hand

Does anyone chamber by hand? I've done so on barrel stubs and they look as good as those done in the lathe.
 
Yes.

I have done several by hand and they come out just fine if you are very careful. I mounted the barrel muzzle up in a vice and used a 3/8" chuck to hold the reamer so that gravity kept the reamer from biting in. It's slow but I can't see any difference in the outcome using a borescope. I use a lathe now because it's faster and I now have one big enough to handle it. I also hand finish my reamers for a smoother chamber finish but that's a whole different topic. I ruined the first one I tried that on and didn't try it again until I started researching cutting angles and reamer sharpening.

Dennis
 
Fred J said:
Does anyone chamber by hand? I've done so on barrel stubs and they look as good as those done in the lathe.
Click to expand...

Fred I didn't want to be so bold as you but I have chambered a few rimfire barrels by hand and they looked great.

The point I am asking with so little metal removed with a rimfire reamer -common sense tells me the reamer has to follow the bore. BUT I'M UNSURE.

I don't chamber by hand simply because I have a lathe and I feel the tail stock keeps the reamer more centered than I can by hand.

I have a good friend before he got a lathe- chambers by hand with the barrel uprite in a bucket and oil flushing the chips down the barrel. I thought what an excellent idea... Maybe he still uses his hand method I don't know but he produces a lot of factory modified 10-22 barrels that are an improvement over stock.

Now back to hand chambering a rimfire centered in a lathe slightly pushing with the tail stock and cleaning often- how can the chamber be off center in a rimfire?
 
I've watched Lamon Loggins chamber by hand with a t-handled reamer holder. He's built a lot of winning rifles in the past, not sure if he's still in business.
I don't chamber by hand because I want to get a proper cutting speed for a HSS reamer. Perhaps I'm missing out on something.
 
The reamer wants to follow the bore, it doesn't have to. Start it crooked and you'll get an out of round chamber. Push sideways and you can get a tapered chamber with a straight reamer. Your assuming that the bore is perfectly straight of course. Your assuming that the lands are all perfectly the same height since that's what your pilot is following while your reamer is following the groove. Your assuming that the bore is actually round and has support all around, try a 2groove. The real question is how much does it matter? I've seen rifles with crooked chambers that shot great. Would they have been better with a perfect chamber? I don't know. I try to get everything as perfect as possible on the assumption that perfect is better but I really can't prove that. My wife has a 40X that should not shoot, the chamber and leade have large machine marks and the barrel is so large that it doesn't even wipe the wax off a bullet when you slug it. It still shoots 250 20X targets. Go figure. .22s are just a real pain in the butt because they seem to defy common wisdom way to often.

Dennis
 
Something to think about ?

Joe,

I was hoping that someone with experience making RF chambers----using the set-up methods recommended on this board for CF chambers----would chime in with similar methods for RF chambers. No such luck yet.

I've never done a RF barrel and am pretty much a greenhorn with a lathe. However, I've learned to use the methods recommended here for CF barrels with very good results.

I've used the Gritters method of dialing in from the throat rearward and the "2-point" method of setting the throat and muzzle on the spindle center. I can't tell that either method groups any better than the other but each method has it's advantages and disadvantages.

After looking at the SAAMI specs for the 22 LR-----Match and Sporting chambers----I think you might be able to do a RF chamber with the Gritters method, using a piloted reamer as you mentioned. I think my skills will allow me to do this and some here might also be able to use the "2-point" method.

I think that if you center your bore at the breech face and maybe as much as 1" forward of there----you can use a floating reamer holder or floating reamer pusher, along with your piloted reamer---you can cut a well-aligned chamber.

You have a bit of help from the reamer----if per the SAAMI specs-----in the form of a 5 degree taper at the forward end of the case body portion. This----I think----would help you get the reamer started on line, especially if you single-point cut a slight cone at the breech face.

As mentioned, this is from a greenhorn who has never done a RF barrel-----but----if I had the barrel and the reamer, I'd at least try the set-up. If you screw up, you've only lost 1" of barrel.
Maybe someone else will come along and correct some of my thinking.

Good luck to you.

A. Weldy
 
I think I would bore a rimfire chamber, no reamer......... But I'm talking out my orifice here, never done it, but can't envision a problem.

I know it sure works well for shotgun, pistol and various straightwall chambers for Sharps, Rolling Block and similar plonking rifles.

al
 
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