Pleasant surprises with my old .270 winnie

[Mr. Magoo]

Definitely more to the Sherman designs than higher velocity.
The shorter and fatter cases SS and Max cases are easier to tune and keep there, and in his words "the efficient ones usually are."

10-4.
I'll be reading a bunch more about it, trying to learn. That's part of the fun for me.

Right now I'm working on consistency in my ammo and practicing my shooting technique. It's been too long since I burned much powder and I'm rusty.

 

[DylanWalsh]

Funny how things come full circle. That old 270 has great ballistics!

 

[Pilsner]

Yep. Before using the berger calculator I wouldn't have imagined stabilizing 170s in a 1:10 was possible even at my elevation.

I checked and got a 1.7 which is "marginal" at my altitude of 2370'
Said it should shoot well but BC numbers might not match or some such.
Not sure what that means but I'll pick up a box of heavy bergers if I see them to play around with.

 

[Capt Nag]

I I've played around with heavy for caliber bullets in my .270 and .270 WSM. Once I hit 165 gr. on up, I get keyholes. Your elevation has a lot to do with it as well.

Key holed because the twist rate doesn't support heavier bullets.
1-10 twist is the usual twist for a .270.
130-150 grain bullets are certainly in the Goldie Locks Zone.
I used 90, 100 110 grain Sierra bullets on smaller game like Coyotes and Antelope. The 100 & 110 were terrific on Antelope. They shot well enough but it was obvious that my Remington perfered the 140 gr Sierra SPBT to anything.
It was deadly on Elk and flew straight.

 

[Mr. Magoo]

Key holed because the twist rate doesn't support heavier bullets.
1-10 twist is the usual twist for a .270.
130-150 grain bullets are certainly in the Goldie Locks Zone.
I used 90, 100 110 grain Sierra bullets on smaller game like Coyotes and Antelope. The 100 & 110 were terrific on Antelope. They shot well enough but it was obvious that my Remington perfered the 140 gr Sierra SPBT to anything.
It was deadly on Elk and flew straight.

The moral of this story is that it all depends on the elevation they're shot at. That has to be included in any conversation about twist and bullet weights. I thought that was super clear here but maybe not.