Gunsmithing 300wm freebore?

[Seth8541]

Just had a 300wm built on a REM 700 action, 26" 1 in 10 Kreiger. When bullet is loaded to max magazine length I have .30" of jump to rifling. I've read that magnum cartridges have an extended freebore to control pressure and velocity. Does .30" seem like too much? Have not shot it yet, just wondering if this sounds about right. Thanks guys.

Seth

 

[TAC]

Re: 300wm freebore?

What bullet weight are we talking about and what did you specify?
This may be the problem since you have not specified what you ordered. A smith without direction is going to chamber a barrel to SAAMI specs.

Ask your smith how he set it up. If you want it shorter he will have to set the barrel back a bit.

I know this doesn't help now but its best to order a reamer with the dimensions desired that way you will have the same dimensions on the next barrel you chamber down the road.

T

 

[MikeeBooshay]

Re: 300wm freebore?

Yes before you pick a reamer/chamber ( regardless of the caliber ) it's best to have some idea of the bullet you plan to shoot thru it. For that matter, that is necessary info to pick a twist rate on the barrel.

I have a great shooting 300 WM, but it is very short in the freebore. Loading rounds past the factory length, is not possible without significant jamming into the lands, like +.150". Not so good if you have to cycle an unshot round, about half the time it dumps the powder in the action/mag. Good thing for me is that what I shoot in it ( mainly 190 SMK) is they shoot great at 3.350", leaving plenty of room to extend as the throat wears.

Your's,,,,, sounds a bit long, on the other end of the scale. Not so easy to extend your length to accomodate throat wear, if you keep the rifle long enough to worry about it.

If it shoots good now, and you aren't looking for a bit more jam on your bullets, just shoot it. You can set it back later after the throat wears some, and freshen it up, or rebarrel it then.