# 270 wsm or 7mm



## yote slayer (Jan 24, 2008)

I reload so the cost of ammo is not a question although everything is more expensive in the wsm. I am looking at a new purchase but I want to consider these 2 they really stand out to me. Anyone have an opinion and what the positive to both are als negatives?


----------



## Mojo1 (Sep 8, 2007)

I have a 270WSM and a couple of 7mm Mags. Both shoot flat and hit hard. My 270WSM weights about 7 1/2 lbs ready to go, it kicks a little but not as bad as my Model 700 7mm does. My Bar 7mm is a sweet shooter but a little heavy to pack thru the hills, you might not care about the weight, but its' a lot longer in length than the other rifles I have.

270WSM has a good selection of factory loads from the 130 grain thru the 150 range. I shoot the Federal 150 Nosler partition in the 270WSM. It does a great job, and shoots flat.

7mm mags bullet weights go up to 160 grain, I use 140 Barnes X-bullets in mine. 

Both are pretty poplar rounds now days and you can get factory ammo loads pretty readily while on the road if you run out of rounds.

I like the fact that the 270WSM fits a short action verus a long action rifle, I have short arms.

I guess it comes down to the weight and length of the rifle action, if I bought another new rifle today it would be another 270WSM.


----------



## El Matador (Dec 21, 2007)

The 2 are very close in ballistics, but some minor differences to consider. Like mojo mentioned the short vs long action is one thing. The 270 supposedly has a little less recoil, and is a more accurate cartridge, but it's doubtful either of those things would make a difference in the field. I think the only real advantage one has over the other is the 7mm's ability to shoot heavy bullets. Short magnums are known for not being able to handle the real heavy bullets very well, so more than likely the heaviest you would go in the 270 is a 150 grain. You can shoot 160 or 175 out of the 7mm. Personally I would go with the 270 if its mostly for deer, but if its going to be used regularly for elk I'd opt for the 7mm and load up some 175s.

Another caliber to consider is the 7mm WSM. Its actually superior to the 270 in performance because of the fact that the shoulder is .100" further forward so it holds more powder. It will give you about 100 fps over the 270, but it probably wouldn't handle the 175s as well as the regular 7 mag. It's also not as common as the 270 so a lot of rifles aren't chambered for it.


----------



## Frisco Pete (Sep 22, 2007)

I don't really think that you can go wrong with either the .270 WSM or the 7mm WSM. Both are basically identical performers in the field, with all the virtues of the short/fat/beltless case. It really comes down to individual preference. The .270 WSM is chambered by more different rifle manufacturers than the 7mm WSM, which may be a deciding factor. This is partly because Winchester/Browning were late in actually coming out with rifles and ammo, and because Remington has their own competing short 7mm Mag - the 7mm RSAUM (_Remington Short Action Ultra Magnum_).

As a reloader, you can also easily de-tune the Short Mags a bit with a little less powder to duplicate .270 Win or .280 (or 7mm-08) velocities, and do so with less pressure to boot. For the most part they are quite reloader-friendly.

If by "7mm" you really mean the belted 7mm Remington Magnum - in that case I would strongly urge you to forget it and go with either the 7mm WSM or .270 WSM because... (read following paragraph) If you mean 7mm WSM you can stop right here.

********************************************************************

The 7mm Remington Mag seems to have the most variations in chamber dimensions of any hunting cartridge I have ever seen. This is partly because it headspaces on the belt, not the shoulder, so manufacturers can save some re-tooling money and get a little sloppy with the chamber. Even the reloading manual engineers wring their hands and get gray hair trying to come up with a safe load that works with so much chamber variation between rifles. So they and the factories try to compromise on the safe side - which tends to back-off the load from advertised velocity - fully knowing that most shooters don't own a chronograph, don't reload and care that belted case life is very short, and really have no idea that there is a _good_ chance that their ultra-killer 7mm Maggie is really a .280 Rem - unless they are lucky enough by accident to have a chamber that allows it to attain magnum velocities. Sometimes ignorance can be bliss!

The new 7mm WSM (and smaller RSAUM) headspace on the shoulder and have much tighter, and _much_ more uniform chambers; and the ammo seems to run around advertised velocity. Efficiency and accuracy seem to be _very_ good with this superior combustion chamber design. That is why so many in the industry who are gun-savvy feel they are a better mousetrap. The 160-gr premium bullets they are often loaded with will do anything the 7mm bore is capable of, and IMO, is the best all-around weight in the .284" bore.


----------



## woollybugger (Oct 13, 2007)

> The 7mm Remington Mag seems to have the most variations in chamber dimensions of any hunting cartridge I have ever seen. This is partly because it headspaces on the belt, not the shoulder, so manufacturers can save some re-tooling money and get a little sloppy with the chamber. Even the reloading manual engineers wring their hands and get gray hair trying to come up with a safe load that works with so much chamber variation between rifles. So they and the factories try to compromise on the safe side - which tends to back-off the load from advertised velocity - fully knowing that most shooters don't own a chronograph, don't reload and care that belted case life is very short, and really have no idea that there is a good chance that their ultra-killer 7mm Maggie is really a .280 Rem - unless they are lucky enough by accident to have a chamber that allows it to attain magnum velocities. Sometimes ignorance can be bliss!
> 
> The new 7mm WSM (and smaller RSAUM) headspace on the shoulder and have much tighter, and much more uniform chambers; and the ammo seems to run around advertised velocity. Efficiency and accuracy seem to be very good with this superior combustion chamber design. That is why so many in the industry who are gun-savvy feel they are a better mousetrap. The 160-gr premium bullets they are often loaded with will do anything the 7mm bore is capable of, and IMO, is the best all-around weight in the .284" bore.


Very interesting! (makes good sense)

I don't think a deer can tell the difference between a .270 WSM or a 7mm mag. :wink:


----------



## reb8600 (Sep 8, 2007)

Frisco Pete said:


> The 7mm Remington Mag seems to have the most variations in chamber dimensions of any hunting cartridge I have ever seen. This is partly because it headspaces on the belt, not the shoulder, so manufacturers can save some re-tooling money and get a little sloppy with the chamber. Even the reloading manual engineers wring their hands and get gray hair trying to come up with a safe load that works with so much chamber variation between rifles. So they and the factories try to compromise on the safe side - which tends to back-off the load from advertised velocity - fully knowing that most shooters don't own a chronograph, don't reload and care that belted case life is very short, and really have no idea that there is a _good_ chance that their ultra-killer 7mm Maggie is really a .280 Rem - unless they are lucky enough by accident to have a chamber that allows it to attain magnum velocities. Sometimes ignorance can be bliss!
> 
> The new 7mm WSM (and smaller RSAUM) headspace on the shoulder and have much tighter, and _much_ more uniform chambers; and the ammo seems to run around advertised velocity. Efficiency and accuracy seem to be _very_ good with this superior combustion chamber design. That is why so many in the industry who are gun-savvy feel they are a better mousetrap. The 160-gr premium bullets they are often loaded with will do anything the 7mm bore is capable of, and IMO, is the best all-around weight in the .284" bore.


Where did this information come from? I have never heard that before. I cant imagine the manufacturers would put out a magnum rifle with a chamber that may not handle the magnum velocities. There are a lot of reloaders that will try to get everything they can out of a caliber and the manufacturers know that. They are not going to put out a product that may endanger anyone and lead to a lawsuit.


----------



## Frisco Pete (Sep 22, 2007)

> I cant imagine the manufacturers would put out a magnum rifle with a chamber that may not handle the magnum velocities.


 It is not a question of "handling magnum velocity" It is the sloppiness of the extra large chamber and possibly a long throat that reduces velocity (and pressure) from what it _should_ be, or an extra-tight chamber/ short throat that increases pressure and velocity (hence the reduction of pressure/velocity in 7mm Rem Mag factory ammo over the years.)

Speer Reloading Manual #14 7mm Remington Magnum pg. 400:
"There is quite a variation in published load data for this caliber... Seldom will either handloads or factory ammunition match nominal factory ballistics in a sporting rifle and there is a great deal of velocity variation among sporters in this caliber. Rifles in the Speer lab's collection posted velocities varying from 400 ft/sec under to 300 ft/sec over those posted by the SAAMI pressure barrel with the same ammo. Because of this, we have departed from our usual policy of showing velocities from a sporter. The velocities listed for the 7mm Remington Magnum are from a 24-inch pressure barrel."

The president of Savage Arms in a magazine article a few years ago pointed out some of the chamber issues with belted Mags in general and the 7mm Rem in particular.
Mentions in various articles over many years in some of the more technical gun magazine, like Handloader and Rifle, point out some of the issues associated with variations in belted mag chambers, of which the 7mm Remington Mag seems to be the absolutely worst offender by far. You don't see the same _caveat_ mentioned about the belted .300 Win Mag.
In personally chronographing my own 7mm Rem Mag I found velocity to be quite a bit lower than spec - unless you are shooting .280 factory ammo! Other forum members I know have seen the short brass life when reloading due to case splits just above the belt due to stretch in an overlong chamber (Ruger M77 MKII in one particular case) and this is always mentioned as a possible case life problem in this caliber unless you have a tight chamber (luck of the draw unless you have a custom-chambered rifle).

Hope this helps you understand that there IS an issue there and that this sheds some light on what the manufacturers actually put out.


----------



## Fishrmn (Sep 14, 2007)

Wouldn't own a belted magnum if'n ya gave me one. If'n ya did, I'd either sell it to someone I didn't like, or use it as a crowbar.

Can't stand ta load for 'em either.

Fishrmn


----------

