View Full Version : reaming a chamber question

Bill Siegle
January 6, 2005, 07:31 PM
OK I recently got a lightweight carbon fiber barrel in the standard size for my Ruger 10-22. It has a Bentz chamber on it that is proving too finicky for my tastes. I was thinking of reaming it out to match a standard 10-22 barrel. How hard would that be to do at home. A friend says it is as easy as spinning a reamer by hand a few times but I wanted to check in here 1st before searching out a reamer. Also any ideas on what size reamer I should buy? Any help would be greatly appreciated. Thanks

January 6, 2005, 11:57 PM
Personally, I would at least have someone with a lathe do it. There are probably many hand-reamed success stories, but I haven't been able to do it, at least not to a standard I would call "excellent."

The problem is not reaming straight with the barrel bore. Also, if the stock chamber isn't concentric with the bore, hand-reaming won't correct it.

Even a cheap lathe would excel at this with modest user skill.

January 7, 2005, 09:42 AM
Actually, I do finish reaming by hand. Reaming in the lathe risks misalignment and requires at a minimum a floating reamer holder. I would just buy a Clymer .22 LR reamer from Brownells (#184-150-080). The reamer will follow the existing bore. I like to hold the barrel vertical in a vise with the chamber end pointing up. Turn the reamer with a T-type tap wrench. I have seem people use a Crescent wrench to turn the reamer with, and they managed to oversize the end of the chamber. I like to have a set of headspace guages in the calibers that I ream, but other folks will tell you that you can get by without them. Use plenty of Rapid Tap as a lubricant on the reamer, but wash it off and oil the reamer when you are finished with the chamber, or the reamer will rust.


January 7, 2005, 03:21 PM
Before you go to the trouble of reaming the chamber out, let me ask you a question. What exactly is the trouble you're having? If it is a feeding problem, has the bottom of the chamber face been chamfered at all. Alot of new barrels come in and are very square which will tend to scratch the brass. Look at the empties and check how they look. I have done this to a couple of barrels I have done myself and it fixed the problem. I simply took a knive edge and held it against the bottom of the chamber and worked the blade aginst it. If this doesn't work for you, you can take a polishing stone in a dremel tool and hold the tool down below the chamber and lightly polish the bottom of the chamber, I mean very lightly. All you need to do is get the edge lowered slightly to allow the nose of the bullet to enter and the body of the round to slide up and in instead of dragging and holding there. I would then take a polishing fob with emery rouge and polish up the intire area you just worked on and maybe the upper portion of the chamber as well to make sure it is smooth as well. Make sure not to let the collet of the tool to touch anywhere as this will mess things up for sure.

Also, check your extractor to make sure it is holding the round up against the bolt face, if it isn't, that may be your problem as well. One more thing to check is the headspace of your bolt. If it is very close to .043, then you might have feeding problems with all ammo. Most of the time it is closer to .050 which will feed better, but won't be as accurate. The purpose of the Bentz chamber is accuracy, so if you're looking for better accuracy, leave the chamber as it and check to make sure the chamber is chamfered. If it is chamfered already, I would look at the extractor, it should have a slightly positive engagement angle on the round and the bottom should be chamfered to allow the round to come against the bolt face as well, and it should have good spring out. If I was after extreme accuracy, I would also have the headspace checked or do it yourself with a dial caliper's depth gauge checker. Extend it to the back of the bolt face's recess, then slide the caliper against the raised portion of the face. Take the reading there. You want it to be as close to .043 as possible for the best accuracy. If it needs to be lowered, I would suggest you send the bolt to Randy at CPC. He will not only headspace the bolt, but he will pin the firing pin, jewel the bolt, as well as chamfer the back of the bolt to allow for better feeding as well for $50. You can find him as a sponsor on Rimfirecentral.com It is a very good site with lots of info as well. After all of these things have been done, you then will need to fire the gun and check to see how it handles each brand of ammo you shoot. You most likely will be very happy with the results. Good luck and good shooting. Let me know if you need any help with questions.

January 7, 2005, 04:17 PM
Check out this link at RFC.


Bill Siegle
January 7, 2005, 05:34 PM
Thanks for all the advise guys. I pulled the barrel today and dang it cntryboy1289 was right! Big Ole burr right at the chamber face :) Easy and cheap fix. Thanks again for all the help. Next time I will know to inpect these things beforehand :)

January 7, 2005, 10:47 PM
Glad you found it. I would polish it good after chamfering the chamber.