Roughing vs finishing reamer

[Markus]

Just trying to learn a little bit about this. What is the difference between a roughing and a finishing reamer?

 

[Alpheus]

h ttp://rifleshooter.com/2015/04/chamber-reamers/

 

[guntech]

Just trying to learn a little bit about this. What is the difference between a roughing and a finishing reamer?

The roughing reamer cuts quicker and smaller than the finish reamer. The finish reamer cuts to the correct size. Many do not use roughing reamers, they simply step drill smaller and then finish with a reamer.

 

[Ron AKA]

The roughing reamer cuts quicker and smaller than the finish reamer. The finish reamer cuts to the correct size. Many do not use roughing reamers, they simply step drill smaller and then finish with a reamer.

Good info. I wondered the same. Seems expensive for gunsmiths to keep a roughing and finishing reamer in every cartridge size. I have another question since you seem knowledgeable and practical.

For kind of similar reasons, do gunsmiths use reamers which incorporate the throat section in the reamer, or use a separate throat reamer? I'm thinking for SAAMI reamers it is a universal all in one, but for custom chambers it makes more sense to use a separate throat reamer with the depth determined by the bullet length and twist of the barrel???

 

[guntech]

Good info. I wondered the same. Seems expensive for gunsmiths to keep a roughing and finishing reamer in every cartridge size. I have another question since you seem knowledgeable and practical.

For kind of similar reasons, do gunsmiths use reamers which incorporate the throat section in the reamer, or use a separate throat reamer? I'm thinking for SAAMI reamers it is a universal all in one, but for custom chambers it makes more sense to use a separate throat reamer with the depth determined by the bullet length and twist of the barrel???

I usually order my reamers with a short throat and if they require lengthening, I do that with a separate throating reamer. I have no chambering reamers that cut excessively long throats.

 

[Markus]

Thank you very much for filling me in! I too thought it must be cost prohibitive to have roughing and finishing reamers in each chambering.