Replacing the reamer - when?

[wsftr]

Hi ya,
How many barrels should I have chambered before considering replacing the reamer? Gunsmith says its still sharp and cutting well...
I have 5 chamberings on it now.

[KHGS]

This question is a bit like asking how long is a piece of string! It all depends on the gunsmith’s expertise (how he drives it), the quality of the reamer and the steel it is used in! My primary .308 reamer has cut well over 200 chambers and is still in good condition.
Keith H.

[wsftr]

Thanks
Its a PR&T reamer
Only chambering Krieger's and Bartleins.
Gunsmith sates it is still sharp and cutting well..

So sounds like I'm ok - only asking as I have no reference for reamer life at all.

[Frank Green]

Reamer life like has already been mentioned is very subjective to what you think.

HSS finish reamer or a carbide finish reamer? There are pro's and con's to each but normally the carbide will last longer but you can break it easier vs the HSS. Sometimes but not all the time the carbide reamer won't give you as nice a finish or possibly not cut as nice until you have a couple/few barrels on it. Not all the time but sometimes. Usually the HSS steel reamer is nice from the get go.

Type of steel it's cutting, cutting fluid being used... how hard are you pushing it etc...how the reamer was made/ground and by who made the reamer is another variable.

Also watch the build up on the cutting face of the reamer.

First thing to go on a finish reamer regardless if your roughing the chamber or not is the throat. The throat area of the finish reamer always cuts. The finish might look good but it will start to cut undersize at some point and then after that it will start to smear/not cut cleanly and leave a burr in the throat off the side of the lands. If you see that burr.... that should be telling you something. As I said the throat is the first thing that goes and we see it all the time. No way getting around it.

No we don't use throating tools/reamers at all! If we do....it's very very rare.

I've seen brand new reamers cut like crap but usually over the life of the tool it will not want to cut nice/you will have to make the reamer work harder all else being equal.

When we make ammunition test barrels for 5.56, 7.62 and 50bmg we have to measure and record the measurements for chamber inspection. 10 different gauges for each chamber. There are two dimensions/diameters on the 5.56 barrels where we have less than a .001" tolerance we have to hold. Actual spec is a .0008" tolerance. For an average number we can usually get 80 barrels out of a tool. Sometimes more... sometimes a less.

We just did a batch of 32pcs of 50BMG test barrels. Besides using a roughing reamer we finished the job with just one carbide finish reamer. Towards the end of that batch the finish reamer was working a little harder but finish was still very nice and all dimensions/tolerances where held but we did retire that reamer and I'm sending it back for a resharp. So next batch of barrels will start with a fresh/new tool or a resharpened one either way.

Later, Frank
Bartlein Barrels

[Rich4]

Thanks so much for the perspective on your usage, most of us will never see those kind of numbers especially in short time frames.

[Frank Green]

Thanks so much for your perspective on your usage, most of us will never see that kind of numbers especially in short time frames.

Your welcome Rich!