.270 vs .308

[JD0x0]

my favorite 7 mag handload using a Barnes 140 TTSX and RL22, over the chronograph I get 3,250 fps.

The fastest I've seen out of a 24'' .270 is around 3090fps with 140 grains.

But we have to take into account that a 140 grain .277 bullet has a higher sectional density.
.284 140 grains - .248
.277 140 grain - .261

To keep it apples to apples, we want to shoot either a
.277 130 grains - .242 (@ 3200 fps, it's brushing the 7mm mag velocity) and compare it to 140 grain .284 cal
.284 150 grains - .266 and compared it to a 140 grain .277 cal

7 rem mag 150 grains - roughly shoots 3100fps
.277 win 140 grains -roughly shoots 3100fps

7mm rem 140 grains - roughly 3250 fps
.270 win 130 grains -roughly 3200fps

I would say that...

It can be handloaded to near 7mm Mag ballistics

 

[Jimro]

True, the magnums don't really shine until you get into the heavy for caliber bullets. My favorite in 7mm is the 175 SGK.

Jimro

 

[myfriendis410]

I went back to a couple of my loading manuals and I was shocked to see: you're right! There really is very little difference between the two. You only start to see a real benefit when you get up in the 160 to 175 gr. range in the 7 mm mag. But at that point you are competing with the 30-06 and it really has no great advantage over the -06 either. Good catch.

 

[Jimro]

But at that point you are competing with the 30-06 and it really has no great advantage over the -06 either. Good catch.

Just to illustrate that point.

A .284 175gr SGK in 7mm Rem Mag at 2,750 fps drops below 1k ft/lbs energy just beyond 800 meters.

A .308 180gr SGK in 30-06 at 2,750 fps drops below 1k ft/lbs energy just shy of 700 meters.

A 120 yard advantage at the tail end of over twice the common hunting distance is definitely what I would call "no great advantage" to the hunter. For a target shooter, definitely, the 7mm Rem Mag can take advantage of extremely high BC bullets without much of a recoil cost over the 30-06, so that is a definite advantage in my opinion for that purpose.

When people start talking "muzzle energy" or "maximum velocity" they are fixating only on what happens closest to the shooter, not the part that does the work downrange on the animal.

Jimro

 

[jimbob86]

Now just a minute, Picher: my favorite 7 mag handload using a Barnes 140 TTSX and RL22, over the chronograph I get 3,250 fps. That's a considerable step above what the .270 can do. Ballistically though there is really not much difference WITHIN THE SAME WEIGHT between the .270, 30-06 and 7 mm magnum. It's not a fair comparison though because the .270 shines with a 130, the 7mm mag with a 140-150 and the -06 with 165 to 180 IMO. And there is something to the extra momentum a heavier projectile delivers....

How many grains of RL22 do you need to achieve that? 65+?

The .270 will kill any deer just as dead with 10-15% less powder and considerably less recoil ....

And my .270 shines best with 150gr pills- more efficient .....

 

[Roadkill2228]

The 7mm rem mag has nothing to do with the original question. Nonetheless I can't keep my trap shut and must interject something here. It was said that the 7 rem mag only shines with the 160-175 grainers when compared to the .270. I half agree. Then it was said that it was competing with the .30-06 and not much different. Again, I only half agree. Within conventional hunting ranges of 300 yards and less, yes I agree, the standard cartridges are at little if any disadvantage to the 7 mag. The .30-06 does generate roughly the same muzzle velocity with bullets of equal weight it is true BUT....compare the ballistic coefficients of comparably designed 150-168 grain projectiles in .30 cal vs 7mm. At long range the 7 rem mag completely thrashes the .30-06 and the .270 alike.

 

[Rifletom]

Hmmm. Wasn't going to post anymore on this, but, the last few posts mentioned the 7mmRM. Had me two of 'em. Wonderfully accurate rifles. However, for hunting the Western states only, I didn't need the blast and bang the 7's offered. Sold them both and bought another 30-06. Nothing wrong with the 7RM, not at all; but, for MY use, my Sako .270 Win, my Ruger MkII .308 and my three Ruger 30-06's [one No.1B] fill the bill. Flame suit on.

 

[kraigwy]

Simple solution is to have several of each. I have 4 308's. 5 '06s and 2 270s. I figure I got it covered. However my Model 70 Featherweight in 270 Win is my Go to Hunting rifle.

But for poops and grins, I'll throw this in:

the 150 Hornady IB in 270 sucks for antelope.

but the same round works great on elk.

 

[coldbeer]

For me it's more about the platform than the caliber. I wanted a short heavy barrel with my last rifle something I could benchrest and maybe hunt with. I originally wanted a another 30-06 because I already had the dies and tons of brass but 308 win was the obvious choice for what I wanted to do. I ended up buying a Savage 10psr because I got a really good deal on it and it fits my needs perfectly.

 

[Bart B.]

I used to run 220 Grain bullets through my '06. Anybody ever do that with a .270?

Probably not. But only because they're not made yet.

Nothing prevents them from being used. Especially if their main diameter's .270" and a 1/8ths inch wide rotating band around them's .277" diameter to engage the rifling.

Nobody runs 200 grain bullets through their .25-06, either.

 

[JD0x0]

I'd like to try some 200 grain solids in my .270 just for poops and giggles. See how it does as an 'anti material' round.

A reason why people don't shoot 200 or 220 grain bullets in a .270 is because a 180 grain bullet already has a superior sectional density than most of the common 'big game' calibers, as I probably have stated already.

.264" (6.5mm) 160 grain, SD .328
.284" (7mm) 175 grain, SD .310
.308" (7.62mm) 220 grain, SD .331
.312" (.303) 215 grain, SD .316
.323" (8mm) 220 grain, SD .301
.338" (.338) 250 grain, SD .313
.366" (9.3mm) 286 grain, SD .305
.375" (.375) 300 grain, SD .305
.416" (.416) 400 grain, SD .330
.458" (.45) 500 grain, SD .341

.277'' (.270) 180 grain, SD .335


a 200 grain .277 cal bullet would have a SD of .372
which is comparable to a 300 grain .338 bullet used in the .338 Lapua.
220 grains you're up to .410
You could probably line up a couple of elephants, and shoot through them, with a bullet like that. Totally unnecessary for 99.999% of hunting.

 

[Ruger480]

a 200 grain .277 cal bullet would have a SD of .372
which is comparable to a 300 grain .338 bullet used in the .338 Lapua.
220 grains you're up to .410

Sooo...your answer to the OP is...the .270 beats the .308

That only took 71 posts to get that answer. Not bad.

 

[shaunpain]

I think we're getting into philosophical number debates and I can never understand why people think a couple of hundred fps difference in cartridges would make that much of a difference to target. The fundamental concepts will apply here. Light and fast shoots flatter. Heavy and slower retains more energy. We are talking about negligible differences of numbers in similarly performing cartridges that would fit in the same action. The search for the superior cartridge is a futile one, as they both have compromises built into the design to accomplish a specific task. Shooting far away and don't want to holdover? Go for the .270. Shooting far away but need more kinetic energy? Use the .308. The .308 was designed as a compromise over the .30-06 delivering similar performance in a much smaller and lighter package. I think that's what makes the .308 superior to the .30-06. Ingenuity. The numbers, in this case, don't mean a thing.

 

[Bart B.]

CAUTION: The following includes loading data beyond or not covered by currently published maximums for this cartridge. USE AT YOUR OWN RISK. Neither the writer, The Firing Line, nor the staff of TFL assume any liability for any damage or injury resulting from use of this information.

The .270 Win was the longer-range rifleman's cartridge, since it had a flatter trajectory and maintained it's energy for greater distances than many other non-magnum cartridges. It can be handloaded to near 7mm Mag ballistics, without the need for a belt.

Then I'll overload a 7mm Rem Mag to outdo your idea. The .280 Rem is a better round to load hot to equal it's belted sibling. Check SAAMI specs for CUP pressures to better understand why for all these cartridges. The .270 has the highest, .280 the lowest.

And the .270 is only the equal of all the others for maintaining energy and velocity when the hunting (playing?) field is leveled.

That belt on cases it was originated for did not have more power and pressure nor velocity as objectives on its inception a century ago. It was a box magazine feed and headspace issue modifying rimmed, slight shoulder angled double rifle rounds to rimless one to work in both bolt action ones as well as doubles. Peak pressure was about 40,000 CUP.

 

[Ruger480]

The .308 was designed as a compromise over the .30-06 delivering similar performance in a much smaller and lighter package. I think that's what makes the .308 superior to the .30-06.

That idea started this thread. And it was already stated that 270 is superior to the '06. So in terms of classification, am I to understand that 30-06 is now in third place? Or, have we moved the bar down a bit and put the 06 in same bracket as the 300 win mag?

 

[Bart B.]

Depending on one's shooting objectives, standards and conditions, either cartridge would easily be the first choice. Then the choice gets emotionally shifted based on egos. And possibly veered in another direction by what's politically correct.

As the ruler people use to "measure" all these issues is made of high-grade rubber, anyone's decision can easily be "stretched" to satisfy their whims at the moment. And may well end up grouping the .30 carbine cartridge with the .30-.378 Wby Mag. What's a few tens of thousands difference in peak pressure, anyway? Isn't the goal to get a given bullet out the muzzle at a specific velocity? What if both the .30 carbine and .30-.378 cartridge's peak pressure was the same?

This reminds me of the old British philosophy regarding marksmanship and what's the best way to decide who's the best shot. They finally decided to eliminate as many variables as possible based on their reasoning and the rules were simple; everyone uses the same rifle model and same lot of ammunition. That way, the best marksman will easily surface based on scores shot on bullseye targets. There's no difference between all the rounds of ammo; they're all perfect and exact. Same with the .303 SMLE rifles; all identical and equally accurate. Everybody que's up at the armory and is issued a rifle and several boxes of ammo.

 

[Jimro]

Air Rifle is quite similar, once you start spending more than a thousand dollars for the rifle there isn't a significant difference in performance between FWB, Walther, or Anschutz.

That being said, I wouldn't hesitate to use 308, 270 or 30-06 rifles for hunting anywhere in North America, or most of Africa for legal game.

Jimro

 

[Picher]

Back to the original comparison question, comparing only the .308 Win and .270 Win.

There are significant differences between the two.

* The .308 Win is significantly better in semi-auto and pump rifles because it was designed to feed in the M-14 and machine guns.

Also, .308 Win ammo can be bought with heavier bullets that many hunters prefer for woods use and for heavier game.

*The .270 Win has flatter trajectory, especially with 130 grain bullets (factory or handloads). It's considered by many as more of a field cartridge, opposed to a shorter-range cartridge. Factory .270 Win cartridges have been loaded to more modest pressures than some newer cartridges, it's said, because there are so many older rifles around.

The .270 Win is not often found in semi-autos and pumps, since they're seen as shorter-range or "woods" rifles. (Despite my love of the .270 and .30-06, if I were to buy a semi-auto, Browning lever, or pump, I'd choose the .308 Win.)