Determining a load

[Big Trouble]

Anytime.
Take care.

 

[MagnumManiac]

So a 1-8 twist should be perfect for the 77 smk?

I believe that a 7.5" twist is optimal for 77g-80g bullets depending on length and construction. A 8" twist may be perfect for the Sierra, but not all bullets are constructed the same. Look up Bergers twist rate calculator for that bullet.
I will add, I have never found Hornady bullets to be match grade, their BTO numbers are all over the place and I refuse to use them, let alone spend money on them.


Cheers.

 

[the big greasy]

I believe that a 7.5" twist is optimal for 77g-80g bullets depending on length and construction. A 8" twist may be perfect for the Sierra, but not all bullets are constructed the same. Look up Bergers twist rate calculator for that bullet.
I will add, I have never found Hornady bullets to be match grade, their BTO numbers are all over the place and I refuse to use them, let alone spend money on them.


Cheers.

I just ran the numbers in the Berger website. Says you need to be over 1 to be stable, It said the eldms were marginally stable at 1.21and the 77 smk are around 1.8 and said totally stable. Thanks for sharing this site! So maybe that's why my groups were scattered at 100 yards.

 

[Tiny Tim]

I believe that a 7.5" twist is optimal for 77g-80g bullets depending on length and construction. A 8" twist may be perfect for the Sierra, but not all bullets are constructed the same. Look up Bergers twist rate calculator for that bullet.
I will add, I have never found Hornady bullets to be match grade, their BTO numbers are all over the place and I refuse to use them, let alone spend money on them.


Cheers.

6.5 cal ELDM's from the last box I opened. That's some fine qc right there.

 

[Big Trouble]

Agree with you Magnum. I used the JBM calculator. They hav a great "library" of bullets as well.