6.5-270 (257) Wby Mag...What do I need?

[blueberry]

Before I started my build, I talked to Weatherby. They said they had something in the works... which parent case they wouldn't say. But I'm guessing the 26 Nosler was the push to base it off the 300 case.

 

[blueberry]

Mine is 26" with 8.5 twist.
According to Jay, that should be good because of the increased velocity.
I am going to use 140/142g as main bullet weight. Looking for 3200fps or better.
Check back a couple of posts for the details of my build.

 

[Longtooth32]

Before I started my build, I talked to Weatherby. They said they had something in the works... which parent case they wouldn't say. But I'm guessing the 26 Nosler was the push to base it off the 300 case.

I must of missed it and I apologize. Are you building your 6.5mm off the 300 Wby case or the 257/270/7mm Wby case?

 

[blueberry]

Mine are off of .257.
Specs are at the end of page 2.
I wanted to build my own Accumark because they didn't make one at the time.
My goal is to have a legitimate 1000yd rifle.
Weather permitting, will be able to poke a few at 400yds.

 

[tbrice23]

I've always been a necking-down guy vs necking-up. I dont mind neck turning brass.

But I have ZERO experience with the double radius (venturi) shoulder of Weatherby cartridges.
Would it be preferable to buy to form 6.5 wby brass from 257wby brass or 270wby to form considering the shoulder geometry?

 

[blueberry]

I wasn't too worried about the shoulder because the case was going to be fire formed in the new chamber.

 

[Edd]

Mine is 26" with 8.5 twist.
According to Jay, that should be good because of the increased velocity.
I am going to use 140/142g as main bullet weight. Looking for 3200fps or better.
Check back a couple of posts for the details of my build.

An 8.5" twist may work fine with the bullets you are using but velocity isn't a good substitute for twist. You will need more than 1000 fps increase in velocity to compensate for a 1/2" decrease in twist.

 

[blueberry]

An 8.5" twist may work fine with the bullets you are using but velocity isn't a good substitute for twist. You will need more than 1000 fps increase in velocity to compensate for a 1/2" decrease in twist.

*Hoping the wind (read that chill) will lay down long enough to pull the chrono out and get some real data.

 

[BigBuck74]

I am getting just over 3200 out of my McWhorter with 140 vlds, I think basing the 6.5-300 was a move to keep up with the 26 nosler, however I heard they are struggling with accuracy.

 

[blueberry]

Nice!
Tested a couple of loads with Retumbo and top one averaged 3069fps. Still have a ways to go to get to 3200.

 

[BigBuck74]

I believe I am using N560 or H1000. Can't remember

 

[Longtooth32]

Nice!
Tested a couple of loads with Retumbo and top one averaged 3069fps. Still have a ways to go to get to 3200.

Just got my dies...waiting on the barrel from Pac-Nor...

Heck, I am almost @ 3200fps with my RDF 140s with my 6.5x284, 28" barrel. I think you must have some more headroom...? Using RL26...

 

[Longtooth32]

Well...my Pac-Nor 28", super match, 6.5-270 Wby, med Palma, 6 flutes, 1-8 twist, Savage pre-fit just shipped...

Fun is coming...

 

[Weatherby Fan]

I really think Weatherby should have introduced the 6.5 Wby Mag in the 257,(6.5) ,270 and 7mm Weatherby line of cartridges a while back, it would be a great cartridge and a little bit more sensible than the 6.5-300. jmho though.