8 vs 8.5 twist for 6.5 mm

[Graywolf.260]

What is the thinking on this? I see that the GAP 6.5 SAUM is 8.5 or 8.75 twist. I'm building a .260 and found a Bartlein barrel #3 contour 1:8" twist, any reason not to jump on it? Will be using 120-140 gr bullets.

 

[Rob01]

8 twist will work just fine for those bullet weights. I have an 8 twist in my 6.5 Creedmoor.

 

[jakelly]

My 6.5-06 AI duplicates SAUM ballistics and uses an eight twist, loves 140s.

 

[JRWALLSIII]

8 so you can shoot 140 hybrids in one hole

 

[Bob L Swagger]

What is the thinking on this? I see that the GAP 6.5 SAUM is 8.5 or 8.75 twist. I'm building a .260 and found a Bartlein barrel #3 contour 1:8" twist, any reason not to jump on it? Will be using 120-140 gr bullets.

They all work great, don't sweat it..

 

[Graywolf.260]

that's what I thought, but wondering why they are using 8.75 for the 6.5 SAUM

 

[TO 8217]

I'll be picking up my Gap 6.5 CM #7 contour 25 inch barrel 8.2 twist and I was told it will love the 140's

 

[Bob L Swagger]

that's what I thought, but wondering why they are using 8.75 for the 6.5 SAUM

I have 2 6.5 SAUMS, one is 8.5 the other is 8.75.. They both shoot fantastic. I have (2) 8 twist 6.5x47's and (2) soon to have (3) 8.5 twist 6.5x47's.. They shoot all 6.5mm bullets equally as well as the other... A friend of mine has a 9 twist 6.5x47L and he shoots 139 Scenars into one ragged hole..

 

[South tx]

Have had 3 creedmoors, all 8 and all shoot 140's lights out

 

[Bugholes]

8.5 is enough, but many use 8tw because the "faster is better" mentality is hard to overcome. I use 8.5 for 260s and creedmoors unless customer requests otherwise

 

[Smokin250]

My 260ai in 8.5 that greg built me shoots lights out with 130vlds. Shoots great out to 1000 so far if I do my part.

 

[leadbullet]

i have a 1-8 260 and 1-8.5 6.5 creedmoor, both shoot the 120-140 great, no worries there. a 1/2 twist won't make a dif.
cheers/

 

[jackal1]

I get one ragged hole with 6.5 x 47 with a 8.5 twist and same ragged hole with my 8 twist. Ain't gonna make a difference if you hand load and carefully tune.

 

[HodgdonExtreme]

but wondering why they are using 8.75 for the 6.5 SAUM

Because less twist (provided you are certainly stabilizing the projectile) has several advantages, most notably - less inaccuracy due to bullet imbalance.

The 6.5 SAUM achieves way WAY more than enough speed to get very ample stability factors, even with an 8.75+ twist barrel.

There is no particularly good reason to use more twist than is necessary.

 

[PS-G1_Sniper]

Generally you see 1:8 for like 6.5x47 or 6.5 Creed at the speeds they can send a 140gr, then in my range (modern 6.5 Swede) I can easily get away with 1:8.5 due too my 3000fps velocity, then when you're entering 6.5 SAUM territory 8.75 is no problem.

 

[JRWALLSIII]

8.5 will work great with a 139.....I have yet to see a 8.5 shoot 140 hybrids good in a 47