M14 Forum

jmoore · January 31st, 2012, 02:17 AM

Quote:

Originally Posted by jmoore

Just checked a Clymer reamer: 0.346" neck dia. Huge!

Quote:

Originally Posted by Bamban

That is huge. The necks will get a good workout. If you ever want to try my reamer someday I'll be glad to send it to you. No promise on any accuracy of the finished rifle, just the risk on your part. It is available if you want to play.

Nez

This might be worthy of it's own thread, but having started down the path here, this seems a good place to start:

As you have noted above, the neck diameters of 7,62x51 and .308W all seem to run about the same as other thirty caliber rounds. But the drawings indicate that the chamber and cases should be significantly larger! About 0.005" So the Clymer reamer isn't out of "spec.", it appears the minimum chamber specification is wrong.... Every unfired round checked so far from '60s vintage military to current commercial measures 0.340" max. There's a few '50s vintage rounds somewhere that have yet to be measured, but the disconnect between what should be and what is seems real enough.

Which leads to the question: Do you send out your reamer when you are havig a new barrel done, or do you just specify to the maker what you requirements are?

Buying a 0.010" short chambered rifle barrel seems an exercise in futility if maximum case neck life is desired, not to mention the potential accuracy loss.

Bamban · January 31st, 2012, 07:53 AM

Quote:

Originally Posted by jmoore

This might be worthy of it's own thread, but having started down the path here, this seems a good place to start:

As you have noted above, the neck diameters of 7,62x51 and .308W all seem to run about the same as other thirty caliber rounds. But the drawings indicate that the chamber and cases should be significantly larger! About 0.005" So the Clymer reamer isn't out of "spec.", it appears the minimum chamber specification is wrong.... Every unfired round checked so far from '60s vintage military to current commercial measures 0.340" max. There's a few '50s vintage rounds somewhere that have yet to be measured, but the disconnect between what should be and what is seems real enough.

Which leads to the question: Do you send out your reamer when you are havig a new barrel done, or do you just specify to the maker what you requirements are?

Buying a 0.010" short chambered rifle barrel seems an exercise in futility if maximum case neck life is desired, not to mention the potential accuracy loss.

I send my reamer with re-barreling job. When I shot bench rest we all had our reamers and I would think most of the stool shooters today have their own as well. A common practice back in the days is to stick with one gunsmith and he keeps your reamer. When it is time for a new barrel, which by the way the barrels were pulled at about 1500 rounds, just call the gunsmith. He has all the dimensions on the receiver, you don't even need to send the rifle. The new barrel comes in just screw it in and headspace is spot on. Use the same brass.

I used the 0:341 neck reamer on a couple of bolt guns and in a couple of AR10s. This experimental M1A is the first for this platform. It will be used again.

Did you catch on the freebore? I specified this one at 0.3080. Just like Wylde reamer is at 0.2240, the freebore is the same dimension as the bullets.