roughing and finish reamers

[double g]

Is there any advantage to using a roughing reamer other than to save the life of the finish reamer.
DG

 

[jkohler]

No. You'll be better off drilling out most of the chamber with a twist drill then use a small boring bar and bore out within .010 or so of the shoulder diameter

 

[Keith Glasscock]

I've always wondered on a pre-bore, would it be worth doing to try cut the case taper with the boring bar? Would it improve the tracking of the reamer?

Just wondering out loud - no experience to draw from.

 

[akajun]

Ill disagree here, I just picked up .223 and 3006 roughing reamers at a good price and used them the other day. They cut differently, faster, they dont clog up with chips as fast, looking at them side by side with my finish reamer, they seem to have bigger flutes. While I would not go out and buy one for each finisher I have, I plan on getting them for all my high volume calibers like 308.
btw I ran the rougher in till about .100 short, then finished with the finisher.

 

[STS]

I've always wondered on a pre-bore, would it be worth doing to try cut the case taper with the boring bar? Would it improve the tracking of the reamer?

Just wondering out loud - no experience to draw from.

That's exactly the way I do it. I have several centers that have a caliber specific spud on one end and a cone on the other. Place the spud in the barrel bore and suspend the reamer between the cone and the tailstock. Run a test indicator down the primary relief grind on the flute and adjust the compound until you are tracking the taper of the reamer. Bore away.

 

[X Ring Accuracy]

Is there any advantage to using a roughing reamer other than to save the life of the finish reamer.
DG

Flame suit on, but our answer is no. The roughers do great work but with a flush system, patience, negligible wear on the finisher, takes 15 to 20 minutes finish reamer only. YMMV