7 Twist for 6.5 Creedmoor???

I know 8 is "standard" but tell me if 7" has any advantage.

I would try a 7.5 before a 7, I've done this with some 308 guns (9.5 twist) without any degradation to accuracy and I'm still different enough to say I don't shoot a standard twist

Yes. The main advantage going to a 7" twist would give you more stability (or less chance of the lack of stability) as the bullet goes transonic and into subsonic flight at longer ranges. This distance wouldn't be until 1200-1500 yards, though.

Also, Berger is developing a 155 grain 6.5mm bullet. Rumor has it, that it will need a 1:7" twist. At the speeds of a 6.5 CM, a 155 would be going about 2550 fps, which is pretty slow, even for a good, high BC bullet.

Also, if you were playing with subsonic ammo, it would help stabilize the heavy and slow bullets. 6.5mm subs are fun with the 160 grain RN bullets!

Not for me.

I use a 1:8.5 as it is, and run 140's a tad faster than most everyone else does.

Last time I took it past 1000 yards, was 1350 yards, in July. Any farther and I'll grab the 7 Rem Mag, and 180's.

Agree with Chad.

This would be on a hunting rifle. It appears the Germans are ahead of us on this 7 twist offering in a factory rifle.

The 6.5's I have are

6.5 Grendel one has 1:8 and the other 1:8.4
6.5X54 MS has 1:9 and was designed for the 160gr Round nose bullets even with its less than 2300fps starting velocity. If those bullets were yawing I doubt Bell would have killed over 300 elephants with it.
6.5-284 Norma has a 1:9 and does well with Breger 140 VLDs
264 Win Mag has 1:9 and does good with the Bergers

I do not shoot as far as some and might run into issues past 800 yards if I shot that far but inside 800 no problems running those twist rates. On Range, haven't shot the MS past 150 yards, Grendel out to 600, 284 to 790 and 264 o 500 yards.

If I were trying to shoot the 155VLDs that are on the way a new barrel with a faster twist might be in order though.

I tend to agree that the 155 would be going incredibly slow (probably too slow) in a 6.5 creedmoor.

Some things to consider.

Adding twist rate will often mean a loss in some velocity.

If you want to run the new 155 gr 6.5mm bullets, the 6.5 Creedmoor is not the case I would load them in. It just can drive them fast enough to give better performance than the 140, 147 gr. It would need more fuel, so go to a different cartridge that holds more fuel. Same as a 230 gr .30 cal VLD in a .308 Winchester. High BC, but it'll be so stinking slow, it's not doing any good.

Again, I've had zero trouble shooting a 140 gr a Hell of a long ways, with a 1:8.5 twist 6.5 Creedmoor , and most everyone else has zero trouble with a 1:8.

Hand me a box of the 155 VLDs, and say "make them go". And I'm going to run the twist Berger recommends, and load them in a 6.5 SAUM, 26 Nosler, or some other option that will drive them fast enough.

exactly what I used on my Fierce, brand new, amazing results

Waste of twist

What is exactly what you use?

I am all for faster twist...to a point. Never over twisted a bullet....but don't over think this.

If a specialty application where you can/will seat the new 155s out...vs robbing case capacity in a modest short action case with COL restrictions...then consider faster than 8.

FWIW, I use 8 on all 6 and 6.5s, 9 on 7mm. I like to K.I.S.S.

As to the 8.5 above, cannot argue with success.

One can "tweak things" but often times, folks try hard to "re-invent the wheel" - often the R&D has been done. Granted, Rem strangled the 6.5-308 A-square from the launch.....but Big Green has not been known to make the best of decisions...always focusing on counting beans, which is why they are followers, not leaders.

I've never had any problems shooting a 160 gr Sierra out of my 6.5-06 with a 1-8 twist,and I'm looking forward to trying the 155's when they come out. It sucks that Sierra discontinued the 160 gr 6.5mm bullet,but I have enough to last me the rest of my life for hunting.

Exactly.

Original twist for the 6.5X55 was 1:7.5 but look at the long roundnose bullets they were using back in 1894. The 6.5X54MS in 1903 used a 1:8 twist. So the 6.5 started out with faster twist than say 25 o 270 calibers that used shorter bullets and slower twist to help max out speed.

Remember, bullet stability is based on bullet length, not the weight. The 160 grain Sierra bullet is 1.250" long. A 140 grain Berger VLD is 1.421" long. In an 8" twist barrel, the 140 VLD has a stability factor of 1.61, which is very stable. The 160 grain Sierra has a stability factor 2.52, which is VERY stable. The new 155 Berger will certainly be much longer than the 140 class bullets, and should need more twist than an 8", so I've heard.

I'm very sure that is correct.
And the 6.5 Creedmoor can not drive it fast enough to do any good, so we are right back to two weeks ago.

One has to be careful using long bearing surface bullets (heavy for caliber) which often increases pressure, especially when running say a 6.5 in a case size like an '06, Rem Mag, SAUM, etc. vs. a Swede or smaller. Often the higher vel gives ample velocity, hence RPM's for stabilizating, with a twist rate of say .5 less. So, what works great in a 47 Lapua, Creedmoor, 260, or Swede with say a 7.5 or 8 ROT, might work fine with an 1:8 or 1:8.5" in a larger capacity round, and still keep pressures safe.

Performance is great, though often at a price of barrel life, sometimes terminal bullet performance depending on the bullet, range, and yes, even twist rate. Punching paper and steel might have it's slight preference for "dialing in" exact twist rates for a specific bullet. Often a hunter might prefer not to be on the ragged edge of in-flight stability, as all things change during penetration on game. So being a Hunting forum, if one say wants to use a controlled expansion bullet on larger game, and keep the nose forward for maximum straight line penetration, a slightly faster twists might be appropriate. It is all a balancing act, often a function of application. Too fast a twist, a bullet might tend to explode on shorter distances on game and higher mv/terminal speed using conventional cup/core bullets. Aiming for a softer target using soft bullets and/or high speeds and twists is appropriate. So Lungs vs shoulders if not long distances. Case in point, several deer came out in a field, using a 6BR with 105 Amax, a "soft" bullet, I spine shot a buck at 200 yds facing away from me, from a stand shooting on a downward angle. 8 twist, 2850 mv, .550 BC IIRC. Bullet exploded on contact, almost no penetration beyond the spinal column, DRT. Next deer, seconds later, was a doe, 400 yds, LRF. Double lunged, exit golf-ball sized, deer struggled to make it 20-25 yds. So bottom line, if in doubt, consult the manufacturer of a bullet to get a recommendation on twist. Barrel makers often know the answers as well. So again consult them if you don't have access to those in the know of ballistics and such. Most handloaders likely already have a good deal of knowledge but some newbies are likely always coming into the sport. Not to over complicate things, here, but give some of the "nuances" of how things all tie in together, for those who have less experience. So, to end, twist rates affect in flight accuracy, AND terminal on target performance.

I had a 270 cal 150 Partition turn backwards after the nose portion emptied of lead, so it went base forward after flipping. No problem, at 275 yds, it went stem to stern, shot a Mule Deer in the neck, ended up in the ham, JUST shy of exiting. The killing damage was in the first half of its penetration, the buck did not travel far, but all else equal, I want a twist on the faster side for keeping max straight line penetration when possible, as it might be more an issue with say a mono bullet where keeping the nose forward ensures the maximum frontal area to do damage and trasmit shock. Some of this may be "mental masturbation" as many might term it for lack of better words, but for ME personally, I am a hunter first, and target shooter second. But trust me, I do chase accuracy, in fact far more than max speed, though in a given round, I do value both, great accuracy, and good potential speeds, but safely. SO to wrap up, my biggest fear of over-twisting is mainly, Pressure/Safety when using large for cal capacity rounds, and to a lesser degree to maintain bullet integrity on impact when hunting. Odds are the "nose-forward" thing is why the 6.5x54 MS was highly effective even on elephant, modest speeds helped moderate expansion using long heavy for caliber bullets of high sectional density, giving good straight line penetration i.e. elephant skulls. Such is not the mainstay of most folks hunting, here on this site, I do realize, but the concept remains.

Ever look at the Winchester .264gr Power points used in the 264win mag? Those the part on the outside of the case was smaller diameter more like to barely engage the lands then the part in the case behind the crimping grove is full bore .264. That was Winchesters way of getting around the very long bearing surface, pretty sure then got that from the old round nose military bullets. Todays long bullets do not have nearly as long a bearing surface as those due to the longer ogive used for increased BC.

True, the 129 is another bullet that has a shorter bearing surface as well, giving an easy 100 fps more MV, often running near the same speed as 120s. Another "dual-diamter" is Rem's 150 CL in 7mm. In the end, on this topic - the above note on limited speed in a modest case like the CM, will be a larger concern. Often folks want a certain "threshold" velocity for trajectory. I think Personally a small case thru 260 in capacity nearly ideal for bullets to 130. Granted 140-147s have done very well, but they might be the upper end, depending on bbl length. Not much a good 120-130 won't do in the game fields to most sane distances. Guy I know shot an elk at just under 1,000 yds, 47 Lapua with 127 LRX....25" bbl