Building up on my Weatherby action????


Well-Known Member
Dec 26, 2010
Booneville, Ar
Hey fellas, Picked up a black synthetic Weatherby Vangaurd in 7mm rem mag in a trade and would like to rebuild it to 300WM or 300Rum long range rifle. I read the first sticky and if I understand correctly the boltface and action would work however, I'm concerned about the new rounds fitting in the magazine. Especially using the longer high BC bullets like Berger. I have never had a rifle rechabered in a larger caliber before so any info or advice yal can give is appreciated. Thank's, Brad


Well-Known Member
May 21, 2008
South of Canada and North of Wyoming
If you get your calipers out and measure the mag box, you'll see it's about 3.5" long. The 300 RUM case spec is 2.845 and the 300 WM is 2.620. If you do the math, you have .655 left in the RUM and .88" left in the WM for bullet nose. That doesn't cut it for my .308 bullets. You could use a 180 E-Tip or AB in the WM but you would be seating them deep.

I like the Howa/Vanguard actions but I use them for shorter cartridges. I'm having a 300 RUM built now on a 700 action with an extended box and the regular box is a little longer than the Howa box.

I wont be using any more 700 actions for any more builds. They need a lot of spendy mods if you're going to do it right. So if I do any more longer cartridge builds I'll be using a custom action from the git go.

A 300 Dakota has a case length of 2.55 which is a little better but still would br to cramped for a lot of bullets.

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