.308 reamer spec

[6BRinNZ]

Hi,

I have received a reamer spec which has the case OAL at 2.045, but my new Lapua brass is measuring ~2.005. This is a Kiff reamer spec with .168 freebore for the 185s. It seems to me that the reamer OAL is too long and somewhere around 2.015 - 2.020 would be better.

What reamer dimension for case OAL is everyone else using - do you have any issues with carbon rings if you are using these dimensions?

TIA

 

[ARIZONA_F_CLASS]

If I remember correctly 2.015 is maximum case neck length. I trim mine to 2.005.

If you not sure, you can always chamber the brass and see if they fit properly.

That's also the same FTR reamer that I use.

 

[Jdne5b]

I have a couple chambers, that when I checked with a Sinclair tool, are close to 2.035, so I just trim my brass a little longer. Ive not run into any issues.

 

[6BRinNZ]

have you guys looked to see if a carbon ring is forming? I'm working on conventional wisdom where the chamber length is only .010 longer than case length to prevent the carbon ring... .030+ seems to be too much.

 

[SmokinJoe]

My new Bartlein chambered with a Kiff 308 Bisley Rule of 150 reamer came out at 2.040. IMO, the carbon ring you are worried about is not a problem as long as all your brass is trimmed to the same length. Just to add to the previous, when I was shooting IBS Score to world champion level (2004 SSOY) my chamber was 1.540 & the brass was trimmed to 1.518 - never seemed to create any problems & I never did anything extraordinary to keep the little carbon ring cleaned out. Hope this helps a bit.

 

[XTR]

I think 308 shooters worrying about carbon rings would be better served watching out for gollywogs and snarks.

Last week I put a bore scope in three of my barrels chambered with the twin to the above mentioned reamer. No carbon. You are ok. They have 700+, 1500+ and 2500+ rounds in them.

I guess I'd never looked that closely at my reamer print from Dave. I guess I could be trimming all my brass at 2.015 or so instead of 2.005

 

[6BRinNZ]

Thanks guys.

SmokinJoe - thanks for the measurements and the experience.

XTR - its a funny old world - I have a carbon ring forming, I was struggling with consistency from 500+ and eventually had a look with the bore scope, sure enough a carbon ring had formed. I scrubbed it out. Checking 100 rounds later it is forming up again. The plan was to let the brass grow but I will need to trim now. All in all I can keep on top of it, but with the ICFRA suggestion of neck size rules I will most likely get a new reamer at some point, but before I did that I want to see what everyone is doing for the OAL dimension.

Probably something I need to talk to Dave Kiff about but I'm scratching my head as to why reamers would be 2.04+ when new brass is coming in around ~2.005 - maybe some other brands have much longer necks?

 

[thefitter]

You can always have the reamer cut to your own specs. No reason to use a "stock" reamer if you don't like it.

 

[6BRinNZ]

You can always have the reamer cut to your own specs. No reason to use a "stock" reamer if you don't like it.

Yep - I figure there are people a lot more experienced than me using this spec though, it just doesn't seem to make sense to have it so long. It could be no matter what I do I will have a problem with the powder combination I'm using and I would rather be cleaning a ring out of the neck area in the chamber than say the throat if it came down to it.