Any of the pros want to test a reamer?

[Carl S]

If the geometry on any reamer is incorrect it can grab and chatter.to much 'rake' won't help anything.they can also be to sharp.More than normal feeds and speeds isn't always the best way to overcome the problem on a regular basis because there's going to be a fair chance it's going to pick up eventually and snap the reamer and possibly ruin your barrel.Go to the fire often enough and your going to get burnt.if everything is correct,set up,lathe,reamer etc.chambers cut easily and come out good..concentric and to spec.
 

 

[urbanrifleman]

First and foremost, I will not name and shame based on my experience.


I have a carbide reamer. It drives me crazy. It chatters. It grabs. It sounds like drywall screws in a garbage disposal. The cutting edges are very dull, like an insert tooling cutter is.

I have other "common" manufacturers products in carbide that cause me no trouble. I prefer them. I'm very confident in my setup. I have tried the reamer with a barrel stub held snug in a 4 jaw and a rigid holder... same deal. I can kind of make it work with low speed and high/hard feed, but it feels wrong/bad.

Having said all of that... it cuts gorgeous looking chambers, and they don't measure awful. Not great, but not awful - It makes great shooting barrels.

It's a very expensive reamer so I'm interested in feedback from someone with far more experience than me.


If one of the old timers/pros here wants to test it; I'll provide the reamer, a barrel stub, return shipping, and any box of bullets on my shelf.

How many guesses do we get to name the manufacturer?

 

[LVLAaron]

I wont kiss and tell.

 

[LVLAaron]

Just to close the loop on this for future generations - Slowed the RPM down to 150 and pushed hard but not too hard. Cut like a dream. That did end up with slightly bigger chips that the flush couldn't really flush, so it was a little more work than usual.

 

[DShortt]

So....
You've concluded the reamer is fine, but your go-to process is not?

Just asking to learn. No accusations.

 

[LVLAaron]

So....
You've concluded the reamer is fine, but your go-to process is not?

Just asking to learn. No accusations.

Relatively, I'm a rookie at this game compared to the greats around here.

My traditional understanding or carbide reamers was they (like other carbide tools) like more speed. I've used some carbide reamers that cut like butter at any speed, some that need to be run high rpm... and Dave clued me in that some are designed to plow - so I tried this one at a slower speed and plowed. In hindsight it makes sense. The cutting edges of this one aren't sharp, so like a typical turning tool - your depth of cut needs to be at least half of the cutting radius to get a good cut and not just "rub" metal away. Roughly speaking of course.

 

[LVLAaron]

So, I've concluded that carbide reamers are just like brunette girls - they're all unique and require different speeds and feeds. Some lessons in life continue to teach themselves over and over again

 

[critter68]

just curious , what was your original "higher" rpm range?

 

[LVLAaron]

just curious , what was your original "higher" rpm range?

200-500. Got it down to 100 ish (I have a VFD so these aren't exact)

 

[critter68]

thanks for sharing Aaron

 

[Wild Bill IV]

So, I've concluded that carbide reamers are just like brunette girls - they're all unique and require different speeds and feeds. Some lessons in life continue to teach themselves over and over again

You're describing a hot headed red head reamer!!!
The primary cut width and angle determines the rotational speed of cut depending on the diameter of cut which affects the chip angle of curl and chip diameter for that speed and feed!! While the secondary (relief) cut allows for a set clearance for the diameter and width of the flute!! That being said, check that reamer against another reamer of that diameter!! You might see the width and/or angle of the primary cut being different!!! My guess is, it is narrower and/or higher angled!! Thus creating the destructive harmonics at higher rotational speed (Chatter)!!

The true beauty of carbide is its ability to withstand higher heat at the finite cutting point while the body stays cool (low thermal conductivity, less heat abortion) and its hardness over High Speed steels (HSS)!! Carbide will expand less than HSS during cutting due to these thermal properties!! The downside is it cannot take a very fast shock wave without fragmenting!!! Dropping the tool on a hard surface, catching at very high rotational velocity, or sudden jam on feed!!! Carbide shatters (fragments) while HSS breaks or shears!!