I`ve never made a reamer before & would like to attempt it for a project I`ve been considering for some time.
I want to make an adapter cartridge to fire M1 .30 car rounds in my .308 rifle.
As a result I will need to make a reamer for the M1 .30 car to make the chamber inside the .308 adapter.
Any ideas would be gratefully received.

Thanks in advance

Morton

I've made them from O-1 tool steel.....not the best but will get you at least one chamber.

Mill four flutes using an end mill with .03 Radius on the ends and taper and contour in the lathe.

Heat treat and draw it and if it survives it'll cut a chamber.

I actually left some grind stock and ground the reamer on a surface grinder using a spindex...

crude maybe....but it works!

Good Stuff Vapo

Just for interest, you might want to google "spade reamer" and "half-reamer" to see what you may be able to find about single-flute reamers. I think they are much easier to make, and, though they may cut fairly slowly compared to a multi-flute reamer, they are actually quite sturdy AND easy to sharpen.

You really don't even need a mill to make a spade reamer. Turn the shape of the cartridge you want, and the pilot, using your lathe. then use a file to remove somewhat less than half of the width to create the cutting edge and its clearance(s) while retaining as much strength and stiffness as possible. Then sharpen. Of course, leave the pilot fully round.

Also should flatten a portion of the shank so it will be easy to prevent the reamer from turning when mounted for cutting the chamber.

Old time gunsmiths made a great many reamers themselves this way and they worked just fine.

Here is a link to a commentary on making them, written by Gale McMillan. He recommends using a grinder if you have one, rather than a file for stock removal (for obvious reasons). If you HAVE a grinder, it does greatly reduce the work involved.

http://yarchive.net/gun/barrel/reamer_make.html

Get in touch with Doble Trouble. He's made several reamers and can get you pointed in the right direction.