Thread: 270 in a 20in barrel or 308 in 18in barrel

Originally Posted by Flyblown

.308 Winchester

Hands down the most versatile hunting cartridge.

You can run a genuinely short barrel (16” or even less).
A midway length is perfect (18-20”).
A longer barrel (22-24”) adds a bit of speed if you want it.
The projectile options for the .308 calibre vastly exceed what is available for the .270.
You can run the .308 as a fast varmint rifle with 110gr (>3300fps)…
…or…
You can run the .308 as a slower but very deadly bush rifle with 180gr (~2500fps), or even slower if you choose to use a controlled expansion bullet for less meat damage…
…and…
Everything in between, very competently.

The Tikka .308 has a 1:11” twist and it will run long, high BC projectiles to a point, the limitation being the factory mag which can be solved by getting something like the Waters Rifleman option. Either way, a stout load behind a 178gr ELD-X out of a 20” .308 Win gives you a lot of open country to play with, and impressive terminal performance at range.

Then there is the bonus of being able to easily load the .308 for subsonic use, which is really good fun and sometimes can be extremely useful. (I use .308 subsonic quite a lot for up close goat control.)

The bottom line is that the .308 is a far more efficient, versatile and well mannered case than the .270. The 270 excels with the 130 grain weight class, but ballistically that class is inferior by some distance to the .308’s 165 grain weight class. It is a no contest at 500 meters for me, .30 cal all the way. If you look at the midpoint of 150gr, velocity wise there really isn’t much difference between the two.

One way to look at it is how much extra powder the 270 case takes as a percentage, and then look at how much extra ooommppff you can get for that extra powder. You will find it is not a lot.

What do you get is excessive noise, muzzle flash and unburnt powder in a shortened .270 Win.

So get a .308 Winchester.

Like the man said. The .308 is just more 'efficient' all round.