Broke my first reamer

M

Mram10

Cast Iron

Joined

Dec 17, 2017

• Mar 1, 2019

• #1

Frustrating part is, I’m not sure what I did wrong

Carbide 300wm reamer (used. 1st time using it)
Standard floating reamer holder
205 rpm
Barrel Flush at about 1/2 power
Stainless Rem varmint contour
Pre drilled 1.5” in with .390 bit
Boring bar first half inch to .450

Reamer was feeding extremely well then the cutting oil spray changed a bit and before I could stop it, the reamer broke off in there with about half inch left to go. My guess, it hit the end of the pre drilled section and grabbed??? Chips seemed to be clearing out well. Ideas?

 

Sisk Rifles

Plastic

Joined

Oct 14, 2005

Location

Texas and Kentucky

• Mar 1, 2019

• #2

I have had the same experience. Now days I ream all the way with the chamber reamer. I have cut about 800 with my 300Win mag reamer and it still cuts fine.
Charlie

 

M

Mram10

Cast Iron

Joined

Dec 17, 2017

• Mar 1, 2019

• #3

I should have done that. Faster and forget about predrill with carbide???

 

Sisk Rifles

Plastic

Joined

Oct 14, 2005

Location

Texas and Kentucky

• Mar 1, 2019

• #4

I dont predrill or use a rougher reamer any more.
Charlie

 

M

Mram10

Cast Iron

Joined

Dec 17, 2017

• Mar 1, 2019

• #5

Thanks Charlie. I do it so save my hss reamers, but am considering changing back to the way I was taught. No predrill, hold with wrench and slow slow slow

 

P

pat_j0nes

Aluminum

Joined

Sep 9, 2018

Location

Colorado, US of A

• Mar 1, 2019

• #6

I've never used carbide. With HSS I chamber at somewhere around 100 rpm. At 200 rpm I think it would be harder to feed fast enough to avoid chatter.

I drill and bore prior to reaming. The first pass takes me all the way to the neck. I leave only about .010 to cut with the reamer, if you feed too slow it can chatter. Once you hit the neck it cuts like normal

I've broken one reamer. I had a PTG reamer break a flute off at the first use, cost me as barrel. I suspected a faulty reamer, but they only offer a warranty for a short time and it had passed. Hard telling what your used reamer experienced prior to your failure.

Sent from my Pixel 2 using Tapatalk

 

T

tooleyrifles

Plastic

Joined

Feb 25, 2018

• Mar 3, 2019

• #7

On most barrels I predrill with a caliber specific JGS core drill then go in with the finish reamer. On HSS I run 250 RPM's and carbide 400 with flush oil. Carbide is very sharp. I suspect your reamer grabbed then twisted a bit then broke. I have to watch my rate of feed at times. Hope this helps.

Dave

 

M

Mram10

Cast Iron

Joined

Dec 17, 2017

• Mar 3, 2019

• #8

Pat,
Good point about feed causing chatter. Been lucky there.

Dave,
Thanks. Expensive lesson. I’m afraid it was feeding so well it might have hit the end of the predrill section and grabbed, like you stated. Still need to get the reamer out of my holder today....

 

S

skeeks

Aluminum

Joined

Sep 8, 2016

• Mar 3, 2019

• #9

tooleyrifles said:

On most barrels I predrill with a caliber specific JGS core drill then go in with the finish reamer. On HSS I run 250 RPM's and carbide 400 with flush oil. Carbide is very sharp. I suspect your reamer grabbed then twisted a bit then broke. I have to watch my rate of feed at times. Hope this helps.

Dave

Click to expand...

I do this exactly. We have an issue with carbide chattering sometimes. I've gone up to 600 RPM and the results have been great! 100 PSI through coolant. All the HSS reamers go in at 250 RPM. Zero issues.

 

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Tozguy

Aluminum

Joined

May 22, 2013

Location

Quebec Canada

• Mar 4, 2019

• #10

Carbide 300wm reamer (used. 1st time using it)

Makes me wonder about how much it was used and what condition it is in.

 

D

DMF_TomB

Diamond

Joined

Dec 13, 2008

Location

Rochester, NY, USA

• Mar 4, 2019

• #11

carbide is more brittle than hss. even long hss reamers can vibrate under the right conditions.
.
really long length to diameter ratio tools often are run slower rpm and feed. got nothing to do with a heat or hot chip limit more a vibration limit thing.
.
sometimes a drill slipped in a collet and hole is shallow. obviously if a reamer hits the bottom of a hole that will cause a problem.

 

300sniper

Hot Rolled

Joined

Nov 14, 2006

Location

Greenwood, Ca

• Mar 4, 2019

• #12

I may have a Proof carbon fiber barrel with a customer supplied reamer stuck in it hung on my wall of shame...

 

M

Mram10

Cast Iron

Joined

Dec 17, 2017

• Mar 4, 2019

• #13

300,
Love the honesty. I have turned a couple Rem 700 Barrel projects into tikka by accident .... I should be past that by now