Gunsmithing Question about reamer being over bore...

[QuarterBore Loader]

Hello all,

I am not new to this site but only recently registered. I have decided to have a 260 built.

I dropped my barreled action off to the smith to be trued the other day. When we were discussing calibers, he said his 260 reamer is 25 thousandths overbore. I never thought anything about it. I haven't decided on a barrel yet so I still have time to change my mind as far as the chambering. My question is what, if any problems will this overbore present? I understand it allows me to stretch the bullet out farther. However, will this become a problem reloading? What about problem using a detachable mag, will the bullets still fit ok with this extra length?

I know these sound like weird or anal questions and I trust the gunsmith. It's just that this is my first actual build and I want know if this overbore could cause problem or create more difficulty in load development etc..

Thanks in advance.

 

[maccrazy2]

I prefer to run mine tight so I have some room to chase the rifling and still be able to feed from a magazine.
However the current kreiger barrel I have on my .260 the reamer was made with a longer throat so the bullet has to jump .115 to hit the rifling and it still shoots 142smk's great. In case you are wondering, the reamer was made to the wrong specs and was not discovered until I got the rifle back from my smith. It was a fowl up on my end not the smith who did the work. I ordered a custom reamer and did not get what I asked for.

 

[QuarterBore Loader]

Figured it out, I'm GTG..

 

[damoncali]

I think the term you want is "freebore" - the unrifled distance between the end of the neck and the beginning of the leade (the tapered area of the rifling). The amount of freebore you want depends on the type of bullet you want to shoot and other details. Talk to the smith in detail about that .025 of freebore means for his reamer - in other words, what bullets is it optimal for?

 

[krw]

I don't think .025" freebore is enough. I have a reamer I spec'd at .047" freebore and I can load 123gr SMK to 2.800" oal and the bullet has to jump 0.012" to make contact with lands. I don't see any reason to have less freebore than I have. My 260 has been a little "squirrely" and I have wondered if the short freebore was part of my problem.