Home Forums Hunting & Shooting Long Range Hunting .270 WSM vs 7 WSM

I have a Tikka T3X .270 WSM, that I'm thinking of putting a new barrel on. It's been modified with a full length magnum magazine and bolt stop to allow plenty of room for longer bullets. I handload and would like to use high BC bullets for long range. I'm wondering what the consensus is for a chambering - .270 WSM (8 twist) or 7mm WSM (also 8 twist). I have a good amount of .270 WSM brass, so that makes me want to stick to that chambering. I know 7mm high bc bullets are far more available, but I generally prefer to stick to one bullet. In the case of .270 I would probably go 170 grain Berger Elite Hunter. Intended purpose would be elk, mule deer, and occasional steel targets for fun. Suggestions?

7mm probably can shoot higher BC bullets, plus many more bullet choices.

With that long magazine and 8 twist you can run the .270 140 Superbulldozers with a b.c. of .650 and even their 150's with a bc of .710. I run the 140 Bergers with 71 grains Retumbo at 3250 fps with an extended magazine and long seating as I still have a 10 twist barrel and it shoots so well that I don't want to get rid of the barrel yet. The advantage of the WSM case is that it is the perfect size to run Retumbo and get excellent velocity with 140's and 150's. I think soon there will be more high bc bullets in .277 come out - because of the military adoption of the .277 bore. I myself would not go over 150 grains in .277, preferring a very flat trajectory. Those medium mono Superbulldozers in 140 and 150 grain will outperform the heavier 170 Berger, due to their speed and bc. Apparently, the 170 Bergers do work well though. Think seriously of a 25" barrel rather than 24.

I hadn't thought about a longer barrel but that's a good idea. Used to have a Browning A-bolt 7mm Rem Mag with a 26 inch barrel. Didn't bother me except when I was trying to bushwhack through alders in Alaska, then it was a pain lol. I like the idea of more speed and less muzzle blast that a longer barrel provides. Thanks for the info on the bullets, I need to research those.

Just out of curiosity why the 7mm wsm and not the 7 PRC? The action already has the correct bolt face and you can either modify your existing magazine or get new ones that allow a 3.410 OAL. Seems like ammo and brass would be easier.

But I love my tikka 270wsm so I vote that regardless🤣

Lefthunter, I haven't looked into all the possibilities yet and didn't realize the 7 PRC woud be the same bolt face - that being the case it would certainly be a good option. The more I think about it though, the more staying with .270 WSM makes sense since I have the dies and a good supply of brass. With more .277 bullet options out there like the Berger or the Superbulldozers mentioned above, I probably wouldn't gain enough with the .284 bullets to justify the expense of new dies/brass. Now I just have to convince myself that the higher BC bullets are that much better than the 140 grain Nosler Accubonds I currently shoot at 3200 fps for "long range" hunting (which for me probably tops out at around 700 yards under the most optimal conditions).

Like you I have a 270 WSM and plenty of components for reloading it. If and when I ever need to re-barrel it, I plan to just have an 8 twist 26" 270 WSM tube installed.


Frog----OUT!

If you're going to rebarrel, the 7 PRC is what I'd look at. A 175 high BC bullet at 2950-3000 shoots way flat. I've cartridge gacked the WSMs and several other 7 and 300 cartridges, and various other flatter shooting cartridges specifically for elk hunting. A 7mm case holding 70-80 grains of powder shooting a high BC bullet is hard to beat. The 7 PRC fits in that sweet spot - and can be shot reasonably comfortably w/o a brake if you gun weight around 8-8.5 lbs. Big fan of the bigger 7s. And mid 7s. And smaller 7s. Maybe all 7s.....

I’d be in 7mm WSM or PRC mode, for sure. With a few decent bullet options, the .270 WSM can be pressed into LR service, but if you’re rebarreling anyway, it’s an easier road with the 7mm due the variety of good bullet options and superior BCs. Your .270 WSM brass (or Lapua’s new .300 WSM brass) can be easily made into 7WSM, so you’d really just be into a new set of dies.

I think you can end up in the same place with either. Just seems a lot easier with a 7mm.

Jordan, it's not a big deal to expand the neck of the .270 WSM case, but the 7mm case is 0.033 inches longer in the base to shoulder length. (1.857 vs 1.824 according to my Hornady load manual). I guess you'd jam the bullet in the lands and fire-form the case but would that much case stretch be an issue? I like the idea of being able to use the brass I have but the only fire forming I've done is .22-250 AI and the base to shoulder dimension ends up shorter in that one. Thanks for your repy.

If I were you other than absolutely having put emphasis on .277”, 170 gr loads and a new barrel w/8 twist, I’d definitely contemplate using your current rendition. You first have to ask yourself what your current rifle and 1-10 twist is capable of. It will run 150 gr bullets carrying about .550 - .600 in BC at 3,200 fps at muzzle and yield 2,130 fps impact velocity and 1,520 ft-lbs on target energy at 700 yards. A .277”, 170 gr .660 bullet will get you 3,000 fps at the muzzle and yield 2,075 fps impact velocity and deliver 1,630 ft-lbs of target energy at 700 yards. At that distance the 150 gr bullet drifts 26.2”, the 170 gr drifts 25.1”.

Other than wanting to, you won’t achieve much of anything by the conversion, at least not out at 700 yards. Food for thought. Sink your money into great optics if 700 yards is a goal and go shoot your Tikka in current OEM form.

Thank you Rossimp. Out to 700 I'm sure my current setup will suffice. I'm not sure that my rifle can safely get to 3200 with a 150 but that's a minor nitpick. I get a little over 3200 with 140 Accubonds but I have seen a few ejector marks on the brass so it's kind of a warm load in my Tikka. I have a VX-5 Leupold scope with CDS custom dial and I just need to practice more at long ranges with it to verify that the combo is hitting where it should at longer ranges. I realize the atmospheric conditions will have a bearing on that. I've tested it at 400 and it's right on the money but I'd like to put some milk jugs out from 500 to 800 or so just to see. I'm sure that it will be more than twice as difficult to hit at 800 than it is at 400! Which is why I personally don't plan to shoot any game animal past 700 yards and only with a lot more long range practice under my belt. Maybe I'll just shoot enough to wear the barrel out and then get the fast twist version.

I think in the back of your mind you know a 7mm 180 has a little more margin for error than a 277 bullet for elk, this is the "Long Range Hunting" subforum after all. Don't let a set of dies and buying brass dissuade you from getting what you really want. Its a small percentage of the cost of rebarrelling.
7WSM is the correct choice, and I have a full-custom Nesika 270WSM in the safe!

A .277 140 or 150 Badlands mono with a high bc will certainly be fine at long range for elk as is a 143 grain 6.5mm bullet. Less recoil with a 140 or 150 .277 bullet than a 180 7mm bullet in same size case, so you can build a lighter rifle for the mountains. And.... Lapua brass for .270 WSM via .300 WSM with a simple neck down with f/l sizing die.

A false shoulder does the trick nicely.

So would you neck each case up to .338 or 8mm, then neck down to 7mm to create the false shoulder and fireform each case with about 65 grains of powder and a 7mm projectile at near maximum load to properly form each 7mm WSM case from .300 WSM? Or will necking .300 WSM down to 7mm WSM give enough of a false shoulder?

Both are great. No shortage of excellent high bc 270 bullets these days. There are more 7mm but how many different do you need. A berger 170 covers a lot of ground and you need to go to 180s in the 7mm to beat the BC and not significanlty. Of course, you also get more recoil with the 180 gr bullets at similar velocity as 170s. If want to use factory loads do a 6.8 Western or 7 prc else do the fast twist 270 wsm. I saw Peterson and ADG are doing 270 wsm brass this year plus adg is doing 6.8W. Lot of good stuff on the horizon

Lou

Sheesh. If you are worried 277 isnt enough .007 more isnt the answer. Get a 338 or 375

Necking from 300 to 7mm has worked well for me. No need to go larger, for me. Others may vary.