Home Forums Hunting & Shooting Hunting Rifles The Big 7's: 7 STW v.s. 7 Mashburn v.s. 7mm RUM

Which one of these would you choose to shoot 180 Bergers at over 3000 fps out a 30" barrel? Mainly as a long range rig, and I do reload. Let's hear the advantages and disadvantages of each different caliber. I'm leaning towards a Sendero in 7 STW.

With a 30-inch barrel, they'll all meet your velocity goal easily. The Mashburn will use the least powder to do it, and only needs an '06-length action, but will take more steps to reload, and there isn't any factory ammo available. BobinNH will surely chime in here with more info, I'm sure, but that's the short version.

7mm Shooting Times

I would think a 7 Rem would do it handily out of a 30" barrel, and allow for a little more COAL latitude.

Just something to ponder.

Yep, I was thinking the same thing. I'm headed over to the gunsmith soon to pick up a 28" barreled 7mm Wby and I should be able to hit 3000 fps with 180 gr JLK VLD's without stepping on it hard.

Would any of them do it from a 26" barrel without really driving them super hard?

You can probably get 3100 fps out of the RUM in a 26" barrel, I was able to with H1000 powder, don't remember the powder charge right now. I know it was over 90 grains of powder. The STW might be able to do 3000 fps. I'm shooting a 168 gr VLD at 3200 out of a 28" barreled STW with easy bolt lift and round primers. Haven't tried the 180 out of it though.

My STW is a Mdl 70 that was chamber reamed from 7Rem Mag to 7STW.
It has a 26 inch barrel.
Loading WC872 powder it launches 162 Hornady BTSPs at 3400 FPS and 160 Partitions at 3350.
I haven't tried any of the 175/180 grain bullets in it but I would bet it would make 3000 easily especially with Bergers.

RUM.

The older I get the more I appreciate lower pressures.

RUM would be my pick too for your needs. You can always put a little less powder in it if it doesn't need it.

They will all do it....

I have never loaded the 180 Berger in anything but have shot the 175 Nosler Partition a good deal and it is no problem to move it about 3075 fps from the Mashburn case with a 24 inch barrel and 73-74 gr of H1000 and still keep primer pockets tight;this has been true in the two rifles we have chambered for the cartridge.I would think that hitting 3000 fps or better from a 30 inch barrel and 180 gr Berger would not be out of the question.IIRC Travis, the custom rifle builder on here has built several Mashburns for clients and has gotten those velocities with 180 gr Bergers.

Looking at data for the STW, the charges are so close to that for my Mashburn that there is scarcely a difference.STW velocities shown in the NOSLER MANUAL are in every regard about what I have seen from the Mashburn.I think Lane Simpson dreamt up the cartridge because 8mm Rem Mag brass was then available,but the idea of a 7mm magnum on full length, blown out Holland and Holland brass was not new and had been done numerous times by other wildcatters,including Art Mashburn, in the 50's and 60's and maybe earlier...none of them had any real advantage over Art Mashburn's design for the 7mm Mashburn Super.

In any event I have only loaded 160 gr bullets for the STW and velocities were no more than what the Mashburn has given with the same bullets.

That said the STW is a good cartridge and what a Mashburn will do, the STW will do.

I have never shot a 7mm RUM...and would not want one. While it will get more velocity than the other two it also takes powder charges in the 80's and 90's to accomplish this,and seems to want a 26 inch barrel...in any event I have no interest in spending the money to find out.There isn't much need and I think the cartridge just burns too much powder for a 7mm bore .

My 7mm Dakota....which us the equivalent of the Mashburn....has been averaging around 3050 fps with H1000, and a 24" bbl.

The STW case and a 28+" bbl aren't necessary to achieve the velocity you're looking for.

The STW does have the advantage a readily available factory brass, however.

Agreed.

7mm Weatherby might be worth considering - similar to 7 Rem, but longer neck. Available load data probably assumes free bore of Wby barrels.

I have both if i could only have one it would be the RUM. You can always load down hard to go up. Plus brass is easier to get. Just my 2 cents

The 7mm on a .300 Weatherby case might be another one to look at. At one time it was the belle of the ball within the 1,000 yard benchrest community. It set the world record for group size at Williamsport in 1970 and held that title for a few years.

Thanks for all the kind replies all, much appreciated.

I think I'm going to be looking for a Sendero in either a STW or RUM. That's a good starting point for a long range set-up; skim bed the action, tune the trigger, throw a nice optic on top and roll with it. I'll shoot the barrel out of which I get, and evaluate the performance. If I'm not satisfied with one of those, then when it's time rebarrel I'll explore another option such as the Mashburn, Dakota, or 7-300 WBY.

I think the STW or RUM will suffice for my objectives, I just wanted to hear some imput from other shooters.

Thanks again guys.

Think the 7mm-375 Ruger is the best of the bunch myself.

I'd like to build a 6.5-375 Ruger. It's a sickness...

Good sickness to have.Often thought a 257-375 Ruger would be a good also.