Homemade chambering reamers

wildcat · February 18, 2000, 07:13 AM

I have been playing around with my lathe trying to make my own chambering reamers.I use the compound feed to get the taper, my milling atachment to make the flutes, and my dremel tool to releve the flutes and sharpen.So far I have only made a prototype that does not conform to the demensions of any known caliber. I tried it in a old 8mm mauser barrel and it cuts as well a the commercial ones that it have used.I can get case demensions from the loading manuals.My questions are how much larger should the chamber be? How much extra length is normal for the neck? How much extra diameter is needed in the neck to be sure of good bullet release?Is there some formula to determine the throat length or should I just measure the longest bullet that I intend to shoot?I used water hardening drill rod is there a better choice that can be hardened without special equipment?

George Stringer · February 18, 2000, 09:04 AM

Wildcat, there are four sets of chamber drawings in the Brownells catalogue. www.brownells.com. You can go to their site and search for chamber prints. I've never made a reamer. I leave that to clymer and those types but if it cuts as well as you say then I'd have to say the steel was fine. George

Alex Johnson · February 18, 2000, 12:29 PM

You may want to take a look at Howe's Modern Gunsmithing book. This has an excellent chapter on making chambering reamers. The other nice thing is that it was written in the 1930's so all the steel they use was water, or oil hardening. Anyway as long as you are getting good cuts with your reamers your doing something right, the only real danger I can see with making the reamers out of carbon steel is that they can be tempermental during the heat treatment stage, especially the quench. I know a few guys that leave the reamer a few thousands over size and after the heat treat they stone them down between centers in the lathe, this can take out a small ammount of warpage that may occur. Some of the air hardening steels, such as A2 are excellent and very tough; however, to be really succesful you should really have access to a furnace when messing with this stuff.

Alex Johnson
NRA, Life Member

wildcat · February 19, 2000, 07:47 AM

Thanks George and Alex.Brownells is a nice site thanks for the link,I have a well worn brownells catalogue this will save me ordering a new one.Is Howes modern gunsmithing still in print or do I need to look for a old copy?I could probably spend my time better other ways but I dont do this for profit it is the chalenge im after.One reason I like building rifles so much is I am a low tech guy and not much really new has happened in the bolt gun world since 1898 .

------------------
Fear a government that fears your guns

Gale McMillan · February 19, 2000, 10:48 AM

You can do very well in making reamers . I generally make half reamers for proto type work. A word of caution is in cutting the throat .f you have a bore scope inspect the lead on the throat Even an outfit like Cylmere has trouble making reamers that will cut the rifling sharp and clean and not push the bur up on the down wind side of the rifling I recommend buying a good neck and throater from some one like JGS and use it to cut the throat. It will last forever and they are relatively cheap

George Stringer · February 19, 2000, 09:10 PM

Welcome back, Gale! George

wildcat · February 20, 2000, 07:23 AM

Thanks Gale good idea about buying the throaters it should speed the process and they are a handy tool to have.If I buy 3 of them they will cover my favorite bore diameters,.257 .280 .308.

Alex Johnson · February 22, 2000, 11:17 PM

Howe's book, I don't think is in print anymore. I have seen some copies for sale on Ebay and you should be able to get hold of one of them there. These books were published in a two volume set. I believe the first volume was devoted more to wood working aspects of gunsmithing (however it could be the 2nd volume as I don't have my copies with me right now) The other volume is the one devoted to metalworking and this is the one you should look at. There was a volume published in the late 70's early 80's and it had both volumes bound together and this would be desirable both from a practical standpoint (it is the latest edition with the most up to date information) and it is cheaper than the early original versions that command premium collector's prices. Both of these books are loaded with useful information and much of it gets extremely complex, making milling cutters, deep hole drills, etc. Anyway one other book you might look at is the Gunsmithing Tips and Projects that is a compilation of articles from the Rifle magazine. There is one article in here on making bullet molds. The methods they use for constructing the bullet cherry is worth a look at. Anyway lots of luck and hope you can find the books, if you can't find them send me an email and I'll see that you get the publishing information from my copies.

Alex Johnson

February 18, 2000, 07:13 AM	#1
wildcat Member Join Date: December 20, 1999 Location: Northeast Kingdom of Vermont Posts: 88	I have been playing around with my lathe trying to make my own chambering reamers.I use the compound feed to get the taper, my milling atachment to make the flutes, and my dremel tool to releve the flutes and sharpen.So far I have only made a prototype that does not conform to the demensions of any known caliber. I tried it in a old 8mm mauser barrel and it cuts as well a the commercial ones that it have used.I can get case demensions from the loading manuals.My questions are how much larger should the chamber be? How much extra length is normal for the neck? How much extra diameter is needed in the neck to be sure of good bullet release?Is there some formula to determine the throat length or should I just measure the longest bullet that I intend to shoot?I used water hardening drill rod is there a better choice that can be hardened without special equipment?

February 18, 2000, 09:04 AM	#2
George Stringer Staff Alumnus Join Date: October 12, 1998 Location: Earlington KY Posts: 2,299	Wildcat, there are four sets of chamber drawings in the Brownells catalogue. www.brownells.com. You can go to their site and search for chamber prints. I've never made a reamer. I leave that to clymer and those types but if it cuts as well as you say then I'd have to say the steel was fine. George

February 18, 2000, 12:29 PM	#3
Alex Johnson Senior Member Join Date: February 16, 2000 Location: Grand Forks, ND Posts: 812	You may want to take a look at Howe's Modern Gunsmithing book. This has an excellent chapter on making chambering reamers. The other nice thing is that it was written in the 1930's so all the steel they use was water, or oil hardening. Anyway as long as you are getting good cuts with your reamers your doing something right, the only real danger I can see with making the reamers out of carbon steel is that they can be tempermental during the heat treatment stage, especially the quench. I know a few guys that leave the reamer a few thousands over size and after the heat treat they stone them down between centers in the lathe, this can take out a small ammount of warpage that may occur. Some of the air hardening steels, such as A2 are excellent and very tough; however, to be really succesful you should really have access to a furnace when messing with this stuff. Alex Johnson NRA, Life Member

February 19, 2000, 07:47 AM	#4
wildcat Member Join Date: December 20, 1999 Location: Northeast Kingdom of Vermont Posts: 88	Thanks George and Alex.Brownells is a nice site thanks for the link,I have a well worn brownells catalogue this will save me ordering a new one.Is Howes modern gunsmithing still in print or do I need to look for a old copy?I could probably spend my time better other ways but I dont do this for profit it is the chalenge im after.One reason I like building rifles so much is I am a low tech guy and not much really new has happened in the bolt gun world since 1898 . ------------------ Fear a government that fears your guns

February 19, 2000, 10:48 AM	#5
Gale McMillan Member In Memoriam Join Date: September 10, 1999 Posts: 411	You can do very well in making reamers . I generally make half reamers for proto type work. A word of caution is in cutting the throat .f you have a bore scope inspect the lead on the throat Even an outfit like Cylmere has trouble making reamers that will cut the rifling sharp and clean and not push the bur up on the down wind side of the rifling I recommend buying a good neck and throater from some one like JGS and use it to cut the throat. It will last forever and they are relatively cheap

February 19, 2000, 09:10 PM	#6
George Stringer Staff Alumnus Join Date: October 12, 1998 Location: Earlington KY Posts: 2,299	Welcome back, Gale! George

February 20, 2000, 07:23 AM	#7
wildcat Member Join Date: December 20, 1999 Location: Northeast Kingdom of Vermont Posts: 88	Thanks Gale good idea about buying the throaters it should speed the process and they are a handy tool to have.If I buy 3 of them they will cover my favorite bore diameters,.257 .280 .308.

February 22, 2000, 11:17 PM	#8
Alex Johnson Senior Member Join Date: February 16, 2000 Location: Grand Forks, ND Posts: 812	Howe's book, I don't think is in print anymore. I have seen some copies for sale on Ebay and you should be able to get hold of one of them there. These books were published in a two volume set. I believe the first volume was devoted more to wood working aspects of gunsmithing (however it could be the 2nd volume as I don't have my copies with me right now) The other volume is the one devoted to metalworking and this is the one you should look at. There was a volume published in the late 70's early 80's and it had both volumes bound together and this would be desirable both from a practical standpoint (it is the latest edition with the most up to date information) and it is cheaper than the early original versions that command premium collector's prices. Both of these books are loaded with useful information and much of it gets extremely complex, making milling cutters, deep hole drills, etc. Anyway one other book you might look at is the Gunsmithing Tips and Projects that is a compilation of articles from the Rifle magazine. There is one article in here on making bullet molds. The methods they use for constructing the bullet cherry is worth a look at. Anyway lots of luck and hope you can find the books, if you can't find them send me an email and I'll see that you get the publishing information from my copies. Alex Johnson