29 January 2004, 07:35
GeorgeSRecommended barrel dimensions for .458WM
A question for those of you who actually own a .458WM:
in anticipation of a new .458 built on a LH M-70 action (currently a .300Win.), what barrel dimensions do you prefer/recommend?
The gun will be shot with all manner of loads, from 'plunking' 300gr. to maximum DG hunting loads (with bullets weighing 480grs.-500grs.).
I'd like to stick with the factory stock (after it's been reinforced and steel bedded), so please no grossly oversize barrels.

George
29 January 2004, 07:45
RobgunbuilderGeorge- Try the Pac-Nor #5 profile and end up with .750- .850 at the muzzel. I assume you are not going with a brake. Too bad it's a win Mod 70 action as you won't be able to fit a long throat 458 in the box.-Rob
29 January 2004, 08:37
POP.800 or so in the muzzle, and no more than 24" in length.
29 January 2004, 08:44
500grainsI think mine is .700 at the muzzle. Works fine.
The velocity difference between a 27" .458 win mag and a 20" .458 win mag is about 50 fps. There's just not that much powder in the case, and the bore is big so the barrel volume is enough to burn most of the powder in 20", hence the small gain for additional inches.
29 January 2004, 13:17
ScottSI figure your ignoring this, but just in case you aren't, and since I have owned a couple.
Muzzle diameter - 0.75" to 0.78"
Barrel length - 22" to 24"
I do not know what Rob is talking about, and he probably doesn't either, but you most certainly can fit long throated 458 WM rounds in a M70. I know I have done it many many times. As a matter of fact, the enormous lead of the Winchester factory chambers, make it practically impossible to shoot cast bullets accurately in a M70. For the record, with a 3.34" magazine box, I was unable to seat a 500 gr Hornady SP out far enough to touch the riflings in my M70 Post 64 Supergrade, 458 WM.
Thought I would be nice and post this, just in case, you decided to tune back into reality for a couple of minutes.
Scott
29 January 2004, 13:28
LongShotRXGeorge, the Douglas 5A is the best contour I have found.
Joe
29 January 2004, 13:39
BigBulletGeorgeS,
I concur with the #5 contour Pac-Nor. I used this barrel on a Mauser 98 action and find it to be a very good balance at 24". Now, when I put that together in a stock, I found the whole rifle barrel heavy but only weighing 8.5lbs. This allowed me to add about 2lbs of lead to the butt stock and this gave a good even balnce and brought the total weight of the rifle up to 10.5lbs. The extra weight is very good

.
BigBullet
29 January 2004, 14:09
GrandpasezGeorge-Sounds like you are going to reload, so get the longest barrel you can stand , for if you use ball powders you will get some good increases over the barrels the short
crowd likes to use.My original 458 Ruger barrel was .815
at muzzle and 1.2 at breech. Helps tame recoil.Ed.
29 January 2004, 15:58
Frank MartinezRob. wouldn't adding a longer mag box allow that to happen?
Frank
30 January 2004, 02:18
MauserAre you talking about the most loved 458 Winchester? A "light" #5 contour with a muzzle diameter of around .700" and 22" in lenght is just about prefect for me in a 458 caliber. I have followed Robgunbuilder's advice before to use a heavy and long barrel, muzzle brake, etc. and ended up with a rifle that is too muzzle heavy and is too unwillingly to shoulder. I am a little wiser nowadays when it comes to picking a barrel for a big bore. When I pick up a rifle and if it feels too muzzle heavy and awkward then it is an immediate turn off for me to shoot it. Just my 2 cents worth!
Quote:
A question for those of you who actually own a .458WM:
in anticipation of a new .458 built on a LH M-70 action (currently a .300Win.), what barrel dimensions do you prefer/recommend?
The gun will be shot with all manner of loads, from 'plunking' 300gr. to maximum DG hunting loads (with bullets weighing 480grs.-500grs.).
I'd like to stick with the factory stock (after it's been reinforced and steel bedded), so please no grossly oversize barrels. 
George