7mmSTW vs 7mm remington ultra mag

Lefty7mmstw

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well.... I have both and they are rather close; the 7rum will burn more powder (with a standard chamber) and return a bit more vel. at the same pressure. My current 7rum is a short throat... about .2" vs. .5" or so for factory and for all intents and purposes runs like a 7mmstw charge and vel. wise. Both my 7stw and 7rum are 8" twist bbl.s so I'm spinning rather hard; the 7run eats the 175 eld-x pushed by 50bmg and my 7stw is running either the 183 sierra with retumbo or the 140 ab and rl25. I need to play with seating depth a bit more on the 183 and run them over the Oehler again but both are running 3K to 3100 on a 180'ish... The 140 gr 7stw load is 3350 fps as of a couple hundred rounds back.

I'd go with whatever you can get a brass supply for and enough powder/bullets to feed and not look back...
 

Cowboyblaster

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Thanks im building a 7mmRUM right now but i was curious about the stw just because ive heard it mentioned quite a bit. The rum im building we are just working up some load data on it and tried it with 168gr bergers just for their reputed accuracy. We've chronographed the load at 3240 to 3260 with the 1/9.5 twist 26" barrel the two cold bore shots i took with it went through the exact same hole no widening of the hole or anything. My reloading guy says we should try a few tenths of a grain up and down from that load .im not sure you can get better than perfect but hes adamant about it. But as you were saying im surprised at how deep were having to seat these bergers. We are also using h1000 and 87 grains of it
 

Cowboyblaster

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Ive got the 1/9.5 twist 26" barrel so we went a hair lighter with the bullets and using the 168 vld bergers but still in development stage and changes to bullet make or powder are still doable just trying to figure out what is best for this rifle before i load up the 100 casings i have for it. As far as the rifle is concerned i just have left is to put some glass on it that will do it justice
 

Bghunter338

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I have had both. I'm sticking with my stw. I ended up selling my rum because it use more powder then the stw with no more gain. I was able to do it with less powder in my stw. So now I'm having a new stw built with a 7.5 or 8 twist to run the heavy mono's. It's probably going to be a single shot so I can run the bullets long. My current stw now is a factory sendero running the 175 eldx's at 3185fps at 2000 feet with rl26.
 

Cowboyblaster

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I have written down and will be checking my notes should i ever build another big 7 . 1/8 twist barrel recommended . Im learning more every time i ask a question on here so thanks for your input lefty7stw. I also am a left handed shooter. I do everything else right handed. This 7RUM im building has a boyds laminate thumbhole stock rh so it's not a rifle ill be keeping
 

Cowboyblaster

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I have had both. I'm sticking with my stw. I ended up selling my rum because it use more powder then the stw with no more gain. I was able to do it with less powder in my stw. So now I'm having a new stw built with a 7.5 or 8 twist to run the heavy mono's. It's probably going to be a single shot so I can run the bullets long. My current stw now is a factory sendero running the 175 eldx's at 3185fps at 2000 feet with rl26.
Geeze your running close to the same velocities as my RUM with a 7gr heavier bullet getting a little better than 3200 with a 168gr berger vld h1000 87grs of it
 

MagnumManiac

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Having played with a Rem 700 SPS when the 7RUM came out, for the amount of powder used and the ACTUAL velocity we got from both factory and handloads, I will have to say the STW is more efficient than the RUM.
Having gone out this past weekend to shoot a few seating depth loads with the 168g ABLR in my new STW, before getting thoroughly bogged to the diffs in my 4x4, I think the 9.25” twist on my rifle is just too slow at the elevations I hunt at.
The rifle shoots fine at just above sea level, but changes both velocity and drops at 3000’-4500’.
My other rifles I was testing do not do this, had my 300WM Sendero and 375 Bee with me and they both shot as expected.
Has anyone else experienced anything similar? I am using Retumbo and it has gone very cold here already, temps on the day were 3°C while I was shooting.

Cheers.
 

FEENIX

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Thanks im building a 7mmRUM right now but i was curious about the stw just because ive heard it mentioned quite a bit. The rum im building we are just working up some load data on it and tried it with 168gr bergers just for their reputed accuracy. We've chronographed the load at 3240 to 3260 with the 1/9.5 twist 26" barrel the two cold bore shots i took with it went through the exact same hole no widening of the hole or anything. My reloading guy says we should try a few tenths of a grain up and down from that load .im not sure you can get better than perfect but hes adamant about it. But as you were saying im surprised at how deep were having to seat these bergers. We are also using h1000 and 87 grains of it
"If" you search, there is plenty of information on both chamberings; There is also a 7MM STW forum.
 

dogz

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I've only shot the 7RUM just curious if anyone has an unbiased assessment of both calibers


RUM has the bigger case, bigger case more speed period.......keep the pressures the same and you'll see that the RUM is the speed king between those two.

Side note and observation over the years I've noticed 3 cases where people hot rod the heck out of them in the name of speed and the STW and 280 AI are two of the 3...............now wait for the believers to loose their tootsie rolls:)
 

ButterBean

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RUM has the bigger case, bigger case more speed period.......keep the pressures the same and you'll see that the RUM is the speed king between those two.

Side note and observation over the years I've noticed 3 cases where people hot rod the heck out of them in the name of speed and the STW and 280 AI are two of the 3...............now wait for the believers to loose their tootsie rolls:)
I guess that's why the 7 RUM has all but disappeared, Yeah it's a tad faster but with all that freebore they didn't impress too many folks, Most all of us tried the 7 RUM. The STW is still the King
 

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