Throating Reamer method?

[preacher]

How does a smith lengthen the throat on an existing rifle? For example, does he have to pull the barrel, ream it to specification and then reheadspace it? Or can he ream the throat out with the reamer through the action? If so, how does he keep it centered/straight? For instance, if I have a rifle with a C.O.L. of 3.25, with the bullet .025" (or is it .0025") off the lands and I want it to be 3.50" with it .025" off the lands, how does he get it there? I'm curious about this...

 

[HomerOz]

G'Day Fella's,

Preacher, a caliber specific throat reamer is used to undertake this task!
Generally, you would remove the barrel and then set the barrel running true in a lathe, to do this work.
No if the original chambering work was undertaken by a competent Gunsmith, the barrel shouldn't need to be re-headspaced but I would test and confirm this, before I removed the barrel!!!

Hope that helps

Doh!
Homer

Hope

 

[257 Ackley]

Yup, the barrel has to come off. Make up a dummy round for the gunsmith who is doing the work and he can be really close to the jump you are looking for. Realize that as the throat wears you will have to move the bullet further out to maintain the same jump to the lands.

 

[preacher]

Thanks guys, I couldn't imagine how it could be done accurately, or be done at all w/o the barrel coming off. Years ago, I read where John Wooters had his stock Remington 700 7mm Rem Mag throated out an extra 1/4". He called it his "7MM Rem Mag Long throat" and got impressive velocities with the 175s and existing powders. My 7mm Express has a super long throat and my 7mm Rem Mag (both Mod 700 factory barrels) has what I call a "normal" throat. My 2 Mod 700 Classic 35 Whelens ( rechambered to AI) both came from the factory with a super long throat, almost freebore, ha.

 

[30-338]

Thanks guys, I couldn't imagine how it could be done accurately, or be done at all w/o the barrel coming off. Years ago, I read where John Wooters had his stock Remington 700 7mm Rem Mag throated out an extra 1/4". He called it his "7MM Rem Mag Long throat" and got impressive velocities with the 175s and existing powders. My 7mm Express has a super long throat and my 7mm Rem Mag (both Mod 700 factory barrels) has what I call a "normal" throat. My 2 Mod 700 Classic 35 Whelens ( rechambered to AI) both came from the factory with a super long throat, almost freebore, ha.

You can do it by hand

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