In the next year or so I plan on building a fast 7mm. I started out wanting a .280 AI, but now I'm thinking about just doing the 7mm mag due to brass availability, price, and a little bit extra speed. Now I'm wondering if I should just go all out with a 7mm STW or 7mm RUM. Is the extra velocity worth the price? Most of my shots will be under 600 yards.
BTW, I already load for the 7mm RM for my dad, so if I went that route, I wouldn't have to purchase a die and accessories. Also, I already have a donor rifle in .30-06 in a Rem 700 (blued action from the early 80's). Do either the STW or RUM need a longer action? I know the bolt will need to be opened up, but other than that, what modifications will need to be made?
I have all of the 7 mags you are talking about at 600 yards the deer won't know the diffrence from the rm mag to the ultra. But if you are like me you start thinking 7mm RM will work but the stw is just a little better on energy then the ultra has just a little more. Go with your gut and shoot the best bc bullet your rifle will will handle .
I had a rem 700 30/06 re-chambered to 7mm mag and love it. I have taken deer out to 638 yards with it, using 162 a-max and 168 berger.
The 7STW will do it "better" , but the loaded rounds may be too long for the magazine, won't be an issue if you single load.
You could also do a two load thing, 160 accubond for close things, (<300 yards), seat to fit magazine and single feed the long range load OR extend the magazine box.