Penetration: 270 wsm vs 270 win?

[paulf60m]

Hello everyone,

I know that on average the 270 wsm will deliver more KE on a target, than the 270 Winchester. So I would like to know if the wsm offers greater penetration and if so, by how much? So if anyone out there has either tested this, known someone who has, or perhaps knows of a website that has, your help would be greatly appreciated.

 

[ArmedBear]

Uh, KE doesn't really mean much. It overstates the effect of 100 fps of velocity as if it makes a round into something a lot more powerful.

What matters to penetration are things like the bullet weight, diameter, shape, expansion (when, how much), etc.

A low-energy non-expanding round that holds together will penetrate a great deal; a high-energy round that expands immediately and a lot can fail to penetrate much at all in some cases.

Whether the cartridge brass is long and skinny or short and fat makes no nevermind.

 

[rcmodel]

Using identical bullet weights and construction, the 270 WSM will likely penetrate less due to it's higher velocity opening up the bullet more and sooner.

A mushroomed bullet acts just like a drag chute on a race car.

On the otherhand, using premium bonded core / controlled expansion bullets, either one will shoot through an elk sideways with no trouble.
How much more do you want or need?

rc

 

[paulf60m]

ok allow me to rephrase the question. Assuming that they both were fired from the same gun, at the same distance, had the same weight, were same kind of bullet ( lets say barnes triple shock) and etc.... would one have more penetration on average and if so would you know by how much? sorry if i was not to clear...thank you for your time and input.

 

[ArmedBear]

All else being equal, momentum will determine penetration.

Momentum = Mass x Velocity

It's the measurement of the tendency of an object in motion to remain in motion.

Velocity for a .270 WSM is about 7% higher than a standard .270 Winchester. So, you would theoretically get 7% deeper penetration for the exact same shot placement, distance, etc.

So the answer is, in the real world of hunting, there's no measurable difference.

 

[paulf60m]

thank you very much rcmodel you have been very helpful!

 

[rcmodel]

ArmedBear
While I agree with you in theory, I still stand by what I said in post #2.

The 7% increased velocity of the .270 Whizzem will open the bullet more & sooner, reducing penetration.

But I really agree with the last sentence.
In the real world of hunting, there is no difference.

To try to answer further, I know of no ballistics testing of rifle bullets that would directly compare the .270 Win to the .270 Whizzem using identical bullets, or any bullets for that matter.
You don't see a lot of amateur or professional ballistic gel testing of hunting rifle bullets because it takes a LOT of ballistics gel to stop them.

rc

 

[NCsmitty]

Welcome to THR, paulf60m.

As the other poster's mentioned, the ballistic differences between the two rounds are negligible and there are too many variables when penetrating game. Hitting heavy bone compared to muscle mass will usually change the outcome for each.


NCsmitty

 

[matrem]

All else being equal, momentum will determine penetration.

Absolutely.. If bullets weren't prone to "mushroom" & deform, and be more likely to do so as velocity increases,that would be considered fact.

 

[ArmedBear]

rc: here's the GMX .30 caliber 150 grain expansion at 3400, 2700 and 2000 fps.

Expansion certainly varies, but with a 7% difference in velocity, I'd hazard a guess that you'd get such a small difference that the difference in penetration would be a wash (i.e. WSM would give slightly more expansion, slightly higher velocity, therefore very similar penetration). But there, I am definitely guessing.

 

[ArmedBear]

If bullets weren't prone to "mushroom" & deform,

Yeah, but luckily he asked about Barnes, which are pretty consistent and made the answer simpler.

Now had he asked about Core-Lokt, it'd be anybody's guess.

And that's why I said "ALL other things being equal." Hit a bone or something, and all bets are off. All other things are never equal in the real world, which is another reason I think that, in a hunting scenario, you couldn't really tell the difference between the two rounds' terminal performance.

That said, a faster .270 will shoot even flatter than a regular one. Terminal performance assumes a hit in the first place.

 

[kdstrick]

If you are trying to decide which caliber to buy, I'd suggest you stick with the ol' .270 over the WSM. The 270 has been around a long time and is proven to be a very effective hunting caliber. Ammo is easy to find. If sales fall, or fail to meet expectations, the 270 WSM ammo will be hard to find. This has already happened with many of the Ultra-mags, 7mm STW, etc... The resale value of your rifle may drop as a result.

As far as the difference in performance between the two calibers, I can only guarantee one thing... whatever you shoot with either won't know the difference.

 

[matrem]

I think that, in a hunting scenario, you couldn't really tell the difference between the two rounds' terminal performance.

No dispute with that.
Get the one you're more comfortable with,and (a lot of folks)don't negate availability.

 

[jmr40]

Using identical bullets the older 270 will probably penetrate deeper than the faster WSM. The faster bullet will slow faster as well.

Many years ago the Alaska Wildlife division tested many different rounds to determine which would be best to protect officers from bear attacks and they found that the standard 30-06 out penetrated the faster 300 magnums at close range. The faster rounds keep moving faster at long ranges, but offer no penetration advantages at closer ranges. The results of that study have been posted numerous times, but I do not know offhand where to find it.

The type of bullet may have a difference as well. The study done in Alaska was done many years ago with jacketed lead bullets. The newer bullets made by Barnes and others seem to not follow the same rules we have used with lead bullets. The Barnes bullets seem to penetrate just fine running them as fast as possible.

 

[DIM]

Last time I used 270, the six pointer was 40 yards away, I know its unfair but I pulled the trigger, it jumped in the air and ran like 80 yards, he got shot 2 inches above the hart with very good blood trail, I used my handloads 130 grain SGK loaded to the max with 57.5 grains of RL 19 its about 3100 fps, well the bullet created 0.27” entry wound and about size of the quarter exit, I think bullet never had a chance to fully expand…

About 270 WSM I never used one, I never had problem with 270 penetrating, if it made entry it will surely make an exit...

 

[berettashotgun]

*Ammo is easy to find. If sales fall, or fail to meet expectations, the 270 WSM ammo will be hard to find. This has already happened with many of the Ultra-mags, 7mm STW, etc... The resale value of your rifle may drop as a result.*

I agree about the ammo, BUT - my Winchester Laredo in 7mm STW is possibly worth more than the 7mm Remington magnum chambered one still in the box

I'd personally believe the .277" diameter bullets at about 140gr & 25-2900 fps will shoot thru about anything walking in the lower 48 with solids.
I use 140's in my Ruger #1 (B) and get some excellent performance with regular old soft point Hornady bullets.

 

[mljdeckard]

What this says to me, is that there is no practical reason to upgrade to the mag from the .270 I already have. (I have never had it fail to do the job anyway.)

 

[Maverick223]

I agree with rc; the .270WSM is likely to penetrate less, due to additional early expansion, and the potential for greater yawing and fragmentation (generally in other manufacturers projectiles, Barnes is likely to hold together). The whissums are a bit over-rated IMO...and I owned one. The ammo is more difficult to acquire and more expensive, if that is a consideration. If you handload the difference in price is marginal, but brass is still more costly and you have less choice in firearms.

 

[ArmedBear]

What this says to me, is that there is no practical reason to upgrade to the mag from the .270 I already have. (I have never had it fail to do the job anyway.)

The only practical reason I can think of would be if the RIFLE in the WSM caliber was lighter, shorter, etc.

However, to use an example of a nice, quick-handling rifle, the 70 Featherweight is 4 oz. heavier and 1 1/2" longer in the WSM than in the old .270.

That's why I consider the WSM to be a bit of a failure. In the real world of real rifles, it doesn't offer magnum performance in a rifle that's the size and weight of a .308-class caliber gun. In light of that, it's just another cartridge, nothing special IMO.

Had it really offered, say, the performance of a 7mm Rem Mag, .300 Win Mag, etc. in a lighter rifle like a 70 Featherweight short action, I would have lined up to buy one. But it simply doesn't.

There is a solitary exception to that: the BLR. In the BLR, the WSMs actually do offer .308-like handling with a lot more velocity.

But in a bolt gun? WSMs work, but the design, as it turns out, isn't all that.

 

[Maverick223]

The only real advantage to any of the whissums is the ability to us a short action, thereby shortening the bolt throw...not worth it IMO.

 

[danweasel]

Assuming that they both were fired from the same gun...

I think if they were fired from the same gun one would have dramatically more penetration than the other. No, I get what you mean, just having fun.

I just shot a .270 for the first time this weekend (One of the new Savage combo models) and I loved it. It is 2nd on my list of "needed calibers" after 300WM. Yes, I am lacking a few things in my quiver.

 

[paulf60m]

well I would like to thank everyone for their info on this topic. One of the main reasons why I originally asked this question, is to help me make a decision on which one to buy.
This coming November, I am going whitetail hunting and need to get my first rifle. In the past, I have gone Whitetail and boar hunting with my dad. His rifle is a Ruger 270.. m77 markII and with the proper shot it seemed to never fail.

Penetration was the only bit of information that I could not find. But seeing as how there does not seem to be a big difference in terminal performance between the two, I think I will stay with what I am familiar with, the 270 win.

 

[DIM]

Good choice, unless you going to pick 270 weatherby mag for long shots

 

[Maverick223]

Wise decision, and you don't need the Weatherby either, as ammo will cost even more (I am assuming that you don't reload...yet).

 

[DIM]

Yeah, if you not planning to shoot anything pass 600 - 700 yards 270 win is the way to go wetherby will let you in 800 - 1000 yards range