Twist rate questions

[jelrod1]

Trying to decide if I should use a 6.5mm 8 twist I have on hand or order another one in 8.5 or 8.7. Building a 6.5 SAUM and planning to push 140 hybrids around 3100 or 130 vld's 3250 or so if accuracy is there. I know the 8 twist wouldn't be needed but just weighing options since I have it. If considering all else equal; powder charges, bullets, ect, would a 4 groove 8 twist Krieger be slower velocity than say a 8.5 twist Krieger 5 groove? Another question is if the combo of 8 twist, 130 bergers, and 3250 would be too much for the bullet. Not as worried on the 140's. I feel the 8 twist will work fine just wondering if things could be better optimized with something else. Thanks

 

[JRS]

I have ALWAYS relied on Randy Robinett, Bill Shehane, and Tim North, to be my go to sources for your very question.

 

[billshehane]

We have done them ( 6.5 SFS ) on 8's & 8.5's but our best results have come on the 5R Krieger & Broughton 9" twist barrels. Don't waste your barrel or time with the 130gn. bullets-- too much powder for not a lot of gain with the lighter bullets. An amazing round with the slow powder and 140 & 142gn. bullets - and don't ask how much powder, just go up in 1gn. jumps and be careful.
Not for every shooter since 16-1800 rounds you'll be back for another barrel. Don't bother startin extra long and cutting it off and rechambering after 1000 rounds or so either-- been there and done that and IT DON'T WORK!!

Have fun with this one- it's a fun- fast - round and extremely accurate when fed the right stuff and the shooter does his job. It likes to go fast and I'm sure thats why you are interested in it.

Good Luck.

Bill Shehane

 

[JRS]

We have done them ( 6.5 SFS ) on 8's & 8.5's but our best results have come on the 5R Krieger & Broughton 9" twist barrels. Don't waste your barrel or time with the 130gn. bullets-- too much powder for not a lot of gain with the lighter bullets. An amazing round with the slow powder and 140 & 142gn. bullets - and don't ask how much powder, just go up in 1gn. jumps and be careful.
Not for every shooter since 16-1800 rounds you'll be back for another barrel. Don't bother startin extra long and cutting it off and rechambering after 1000 rounds or so either-- been there and done that and IT DON'T WORK!!

Have fun with this one- it's a fun- fast - round and extremely accurate when fed the right stuff and the shooter does his job. It likes to go fast and I'm sure thats why you are interested in it.

Good Luck.

Bill Shehane

And that's the rest of the story Coming from the long range guru and conductor

 

[jelrod1]

Thanks Bill for the great info. Time to go barrel shopping.