13 December 2009, 21:58
Twbhunter375 Remington Ultra Mag
I have a extra left hand 338 Remington Ultra Mag and would like to convert to a 375 Remington Ultra Mag. Does anyone have a barrel to sell?
Can some provide specs on there factory 375 Remington Ultra Mag barrel--length , twist, deminsons, etc. Thanks.
Tom
14 December 2009, 00:25
RIPNope, a .375 barrel never lies fallow in my hands, not even a take-off. They all get used.
Use the standard .375 H&H twist, 1:12".
Rifling specs will be the same for the .375 RUM as for the .375 H&H.
The Remington factory 700 LSS that I measured is .650" muzzle diameter at 26" length.
That stainless barrel has a nicely recessed crown from the factory.
That weight is heavy enough to be easily accurate without fuss.
Gives 2803 fps with factory loaded Remington ammo using 300-grain Swift A-Frames.
Hard to improve on that.
Go with a no.4 sporter contour similar to Douglas contours.
That will be close to the factory barrel.
DRG says: "Kiss my liberal grits!"

14 December 2009, 01:20
TwbhunterRiP,
Thanks for the feedback. I miked my three ultra mags see below
7 .645
300 .668
338 .650
I though they would mike the same--either Remington quality control is weak or they differ by caliber.
Tom
14 December 2009, 06:58
McCrayThey're all over the place...I have a factory 338 RUM barrel that is .660 at 26 inches and .655 at 24"...

You can tell PacNor or Lilja to dupe the Remington factory magnum sporter profile and get what you want. To me it is the perfect 375 profile. I have 'em in H&H and Weatherby flavors.
BTW...Lilja has a PDF on their websight that shows a bunch of factory contour measurements.