Home Forums Hunting & Shooting Long Range Hunting Learn me on the 7WSM

I stumbled into the parts, including a Rock Creek barrel with less than 20rd through it, to build a 700 in 7WSM. I have no experience with the round, or any WSM. This will be a fairly lightweight hunting gun build, in a Bansner stock.

How limiting is a short action 700 receiver on COAL?

Is the Hornady brass worth a damn?

The barrel is a 10 twist, and the gun will be used for general hunting. What bullet(s) seem to be the magic pill in these things?

Absolutely any guidance is greatly appreciated. This is more a toy than anything, and if it doesnt work out, I am not really out anything substantial.

In my experience with 300 wsm, it’s tight in a 700 short action mag box. I’d be thinking Wyatt’s box to get some room

The limitations are of concern to the aftermarket custom makers that they have introduced a line of intermediate actions.

Yet, my Borden 300 WSM is built on a short action & still has enough room for 155 Scenar's.

10 twist seems a bit slow for a 7mm barrel. With that twist you may be limited to 140 grain pills or lighter, which means you will have great velocity numbers, but if you are looking to take a long poke at something, you could be at a disadvantage.

Hornady brass has been good to me in the past, provided you don't hot-rod the rounds. In my experience I would put it equal with Winchester, just a bit higher than Remington and below Federal when comparing the big American brass manufacturers. I know some people who have had issues with primer pockets getting loose, but in most of those cases, they were running at max or very near max loads. I would suspect that had they been running Rem or Win brass the results would have been the same.

I could not agree more.

I have a Wby Ultra Lightweight MkV in 7mm Wby mag with a 1-10" twist. It shoots:

* the 140gr TTSXs really well (1/2"-3/4" at 100 yds);
* won't group well with the 150gr NBTs (over 2");
* does not group well with any of numerous 160gr bullets I have tried, except for the the CorBon-loaded 160gr TSXs (those are under an inch).

I shot some Federal-loaded 160gr Trophy Bonded Tips that came out at 3,219 fps, and they grouped over 2". When I looked at the target carefully, I noticed that the bullet holes were oval-shaped, which means that the bullets were hitting the 100 yd target at an angle.

Fortunately, the rifle will do what I need with the 140gr TTSXs (3,280 fps MV) and the 160gr TSXs (3,240 fps MV), and it is nicely accurate with those, but I would much rather be able to accurately fire the 3,219 fps higher-B.C. 160gr TBTs.

I would MUCH rather have it with a 1-9: or 1-9.5" twist, like most 7mm mag rifles have.

Kind of disappointing that Wby made that rifle with too slow of a twist to use most of the bullets available for the caliber--and I tend to like heavy-for-caliber bullets. This is especially odd given that four of the six of the 7mm Wby cartridges that Wby manufactures (weighing between 150gr and 175gr) do not work in Wby's own rifles.

1-10" twist for 7mm seems debilitatingly too slow for 7mm rifles.

I love Wby rifles, but that was a mistake.

YMMV.

1-10 twist????? Can you return it?

It works for what I need. It’s a light-weight mountain rifle, and it should do what I need out to any range I would shoot it. And I’ve got the 340 Wby for longer stuff.

Or did you mean the OP?

I've had two 1 in 10" Douglas barrels on a NULA 7x61 Sharpe & Hart Magnum (about the same ballistics as a 7mm Rem. Magnum) Shoots 140s to 175s very well. A Schultz & Larsen Model 60 in the same chambering with a 1 in 12" barrel shot 160s well, but never tried 175s in that one. I have a Sendero 7mm Rem. Magnum; don't know the twist rate in it, but it does well with bullets up to 160 grains. Haven't tried anything heavier.

I've had three of them. Tough to beat for an all around hunting round IMO, for a handloader anyway. I've only used winchester brass, and had pretty good luck with it. I ran 160 accubonds in the two sporters, not sure they'd work in yours with its twist tho. 180 Bergers in the LR tactical rig.

Hope it you find a decent BC bullet it likes.

It's a free, nearly new barrel. It will be worth the hassle for giggles.

I would build it on a Tikka.

Since I have a 700 action, stock, bottom metal, and a barrel cut for a 700....

With a 10 twist, I'd be in 120 ttsx mode. Basically go with the 257 Weatherby mindset for it...... high speed point and shoot death ray.

Double benefit to going that route is there's no need to worry about mag box length.

Either that or sell the barrel.

I kinda considered that the issue with box length would be a self solving problem due to twist.

Oddly enough, just got a call from the dude who is building the rifle, and has the tube. We got to talking about other stuff, then I asked him about the barrel. He either told me wrong, or I heard wrong, months ago when we fist discussed it, but he assured me its a 9 twist.

They have been making Mark V 7mm Weatherby rifles with a 1-10 twist since the beginning of time

I only shoot Partitions and Accubonds so this may be a moot point for you, but I don't have a COAL problem in my Remington Model Seven 7 SAUM.

I tried that in my rifle. But, the 120gr TTSX (per Labradar) leaves my barrel at an average velocity of 3,338 fps, and the 140gr TTSX leaves at 3,280 fps.

According to the ballistic calculator, at sea level (because of the 120gr TTSX’s lower B.C.):

* at 200 yds downrange, the 140gr/120gr TTSXs are going 2,794 fps/2,797 fps (basically, the same); and
* at 500 yds downrange, the 140gr/120gr TTSXs are going 2,166 fps/2,108 fps.

And, if both are sighted in at 1” high at 100 yards, they both are 33.5” low at 500 yards.

So, I don’t see any advantage for the 120gr TTSX. They both have very similar trajectories out to 500 yds, and the 140gr bullet is going faster after 200 yds. Might as well have the extra 20gr of bullet to hit the animal.

Based on my experience, that is a mistake, unless my Mk V is an aberration.

What bottom metal? If a 9" twist, for a lightweight build I'd go Wyatt's box and load the 180 ELD. If forced to work with a <2.9" mag box, load the 162 ELD and call it a day. The 140 TTSX at ~3300 fps has also been a fantastic 0-300 meter load for me.

Haven't used the Horn 7WSM brass, but I've used some of their other offerings, and it's generally quite good stuff. Not Alpha or Lapua quality, but about as good as the best RP/WW brass I've run across.

If you run the 120 at the same pressure as the 140, you'll see a significant velocity gain.