How Far to Run the Reamer When Chambering

[INTJ]

I was initially told to only go .025 to .040 before backing out and cleaning the flutes on a non flush system for a 6 BRA. I did that for a while but when I chambered my 33-28 Nosler I didn't want to take that long, so I used .100 to .120. I had no issues.

Isn't the idea to keep the chips from packing hard in the flutes and scratching the chamber?

Thoughts?

 

[Bully]

I've gone .050
I did one barrel where I went .100 and didn't like the finish.
I'm not in a rush.

 

[Ramblerman]

Depending on the reamer (PTG usually), even .020" seems a lot to me in certain cases ( like a 20 Tactical...that barrel got involuntarily shorter).. definitely a big difference between calibers....bigger seeming a lot more friendly to a bigger bite. I'm certainly no expert though.

 

[Danny1788]

Just build a chamber flush system and don’t worry about it anymore

 

[Dusty Stevens]

You can go farther at first then go shorter. Remember according to the case taper you may have to go a long ways to clean up a scratch, and once you get closer to the end its not cutting enough to remove a scratch. Always keep your hand on the reamer so you can feel it loading up. If the chips aint flowing its scratching.

 

[gme]

if you pre-bore you can go .200 easily

 

[Will Henry]

My first cut, I go about 5/8" deep. The next cut, about 1/4" as the neck is cutting by then. When the reamer is cutting fully, I go about .050. The last cut is .020" or so. WH

 

[tobnpr]

Don't overthink it, read the reamer and listen to what it's telling you.
Packed with chips when you withdraw, take shorter passes. Just make adjustments as needed- not rocket science.

 

[Gappmast]

A lot is going to depend on the caliber. There is more room for chips, between the flutes, on a 4570 reamer than a 223 reamer.

 

[Nightraider]

I drill and prebore and will run a solid 1", hard and fast at 225rpm.

 

[hoz53]

My first cut, I go about 5/8" deep. The next cut, about 1/4" as the neck is cutting by then. When the reamer is cutting fully, I go about .050. The last cut is .020" or so. WH

Thats with preboring right?

 

[hoz53]

I drill and prebore and will run a solid 1", hard and fast at 225rpm.

I know people that do it for a living dont spend a couple hours on a chamber. Ive gotta find a way to cut back on my chambering time. Dave Manson told me once the optimum rpm to run his reamers and im thinking around 150. ive run them at 70 so mabie i should up my game there. How long do your reamers last? If I can get 10 chambers out of a reamer Im happy, and by all accounts most people get alot more. Thanks

 

[hoz53]

I was initially told to only go .025 to .040 before backing out and cleaning the flutes on a non flush system for a 6 BRA. I did that for a while but when I chambered my 33-28 Nosler I didn't want to take that long, so I used .100 to .120. I had no issues.

Isn't the idea to keep the chips from packing hard in the flutes and scratching the chamber?

Thoughts?

Do you prebore? Use a finish reamer only? Do you use a roughing reamer?

 

[shortgrass]

If you are loping along at 70rpm , and you're not using a flush system but cutting .05, cleaning the reamer and chamber an re-oiling, I'd say you're doing OK. Without a flush you will generate more heat at higher rpm if you're not real careful. And heat is one of the 'enemies' of HS tooling. I'm up around 200rpm if the barrel and reamer tell me "I can". I'm running a muzzle flush @ 30-35# , which is a good flow, but not a total mess (I run cutting oil). I drill and pre-bore to save wear on my reamers. If I take the pilot off I reduce the # on the muzzle flush. A steady flow clears the cuttings and keeps the heat down. The last barrel I chambered, just a few days ago, was a Brux in 7 mag. After dial-in, I was done cutting and head spacing in under 1/2hr. You need to remember though, I'm in a working machine shop daily, with "hands on". If you want to take longer, that's fine. Do whats comfortable and produces good results for YOU!

 

[hoz53]

If you are loping along at 70rpm , and you're not using a flush system but cutting .05, cleaning the reamer and chamber an re-oiling, I'd say you're doing OK. Without a flush you will generate more heat at higher rpm if you're not real careful. And heat is one of the 'enemies' of HS tooling. I'm up around 200rpm if the barrel and reamer tell me "I can". I'm running a muzzle flush @ 30-35# , which is a good flow, but not a total mess (I run cutting oil). I drill and pre-bore to save wear on my reamers. If I take the pilot off I reduce the # on the muzzle flush. A steady flow clears the cuttings and keeps the heat down. The last barrel I chambered, just a few days ago, was a Brux in 7 mag. After dial-in, I was done cutting and head spacing in under 1/2hr. You need to remember though, I'm in a working machine shop daily, with "hands on". If you want to take longer, that's fine. Do whats comfortable and produces good results for YOU!

Hey Shortgrass-- Good to hear from you. Thats a bunch of Good Info-- Thank You.

 

[Nightraider]

I know people that do it for a living dont spend a couple hours on a chamber. Ive gotta find a way to cut back on my chambering time. Dave Manson told me once the optimum rpm to run his reamers and im thinking around 150. ive run them at 70 so mabie i should up my game there. How long do your reamers last? If I can get 10 chambers out of a reamer Im happy, and by all accounts most people get alot more. Thanks

I'm over 200 on few of the popular ones and they still cut mirror finishes. Key is prebore almost all of it out.

 

[hoz53]

I'm over 200 on few of the popular ones and they still cut mirror finishes. Key is prebore almost all of it out.

thats a great piece of info. You use a flush system i take it? Thanks

 

[GenePoole]

Coolant flush is the best thing I ever did to preserve the life of my reamers. I don't do a huge volume like some here, but since switching to through-the-barrel coolant flush, I've had no detectable reamer wear, nor do I get that caked-on layer on the flutes that requires a copper scraper to remove.

 

[hoz53]

Coolant flush is the best thing I ever did to preserve the life of my reamers. I don't do a huge volume like some here, but since switching to through-the-barrel coolant flush, I've had no detectable reamer wear, nor do I get that caked-on layer on the flutes that requires a copper scraper to remove.

Thanks for that info.. Im gonna have to build one of these systems. Do you have to use the reamers with the groove in the pilot?

 

[GenePoole]

I just grind the screw off on the sides to allow more coolant flow.