The UK's Finest Independent Forum for Shooters and Gun Owners. Est 2010.

What is the difference between a roughing reamer and a finishing reamer.

Use a carbide roughing reamer to cut most of the chamber then finish off with a finishing reamer - saves wear on your finisher. Roughers speed up the process as well so most pro gunsmiths will use them for popular chambers.

Because I don't do a lot of work I just use finishing reamers. Very few of my reamers have done more than half a dozen chambers so little point buying a roughing reamer as well.

The most used is my 6PPC but that did about 12 chambers before it lost its edge - but I have three or four 6PPC reamers anyway.

You can get a carbide finisher so you have the best of both worlds but they are more expensive of course.

So are the dimensions of the roughing reamer slightly smaller than the finisher or is it the same size.

To be honest, I've never ordered a roughing reamer. I would guess they are typically smaller than a finisher. Their use is to remove 90% of the metal to save wear on the finisher.

Although I've not used one I've seen them in use - it's a great time saver for the pro gunsmith. However I would think many 'smiths are now speccing a carbide finisher from the word go for popular chambers - I certainly would if I was starting over.

An option some reamer makers offer is to make the roughing reamer to the dimensions of a resizing die. Saving the need for a third reamer.

I have a couple of solid carbide roughing reamers, mostly because they were a sensibly price at the time. The rougher cuts just under size, plus the finish is not as good as the finish reamer, therefore I would probably not consider the ones I use (PTG) as a viable option for sizing dies, even if they were correctly sized, if that makes sense! I can post some pictures of mine if anyone is interested.

Yes please.

Never used a roughing reamer but it's not bad practice to run a 4 or 3 flute core drill down before reaming as a drilled hole tends to wander a bit.

Apologies for being late with the image. Bottom is a PTG solid carbide rougher in .223Rem and top is a BBT HSS 6,5x47 Lapua, both are brand new and unused although they look about the same as my used ones.

I Usually rough out chambers with carbide stub drills. I developed a list now in a spreadsheet that gives the chamber size and the stub drill size along with my CAD drawing and shows how deep I can drill and still pick up the bore with the reamer. Again, it saves a little bit of time and reamer life.

Thanks
I don't seem to be able to see any pictures.