Remington 700 SPS 300BLK 1:7 twist accuracy with super-sonic loads?

[TMD]

The only situation which would not benefit from faster-than-normal twist would be precision, long range shooting. A faster twist can magnify the imbalance which is inherent to bullet eccentricity. The bullet can sometimes yaw as a result and give pooraccuracy. In this case, the slowest twist possible for the velocity achieved is the rule of thumb.

For 300BLK though, where few of us shoot past 300 yards, even in supersonic, a faster twist is more versatile than a slower one typically. I have had good luck with 150gr., 208gr. and 245gr. cast pills. (Super, Sub, Sub) Hoping to try the 125gr ones soon.

shoe

The fastest .300bo loads don't have enough velocity to over stabilize.

[dellet]

The only situation which would not benefit from faster-than-normal twist would be precision, long range shooting. A faster twist can magnify the imbalance which is inherent to bullet eccentricity. The bullet can sometimes yaw as a result and give pooraccuracy. In this case, the slowest twist possible for the velocity achieved is the rule of thumb.

For 300BLK though, where few of us shoot past 300 yards, even in supersonic, a faster twist is more versatile than a slower one typically. I have had good luck with 150gr., 208gr. and 245gr. cast pills. (Super, Sub, Sub) Hoping to try the 125gr ones soon.

shoe

The fastest .300bo loads don't have enough velocity to over stabilize.

That's not completely true. Many of the thinner jacketed bullets as well as the FMJ and things like Partitions have problems in a 1/7.

It's easy to hit over 240,000 rpm in the 110 grain bullets and that's the upper limit for some of the varmint bullets.

Sig has gone to 1/6 in a 16" barrel so a 110 grain bullet at 2400 Rpm will be turning 288,000, equal to 4400 rpm in a 1/11 twist.

Lehigh's 78 grain CQB bullet designed for the 300 Blackout can only be ran about 2600 fps in a 1/7 and last I looked is no longer for sale because kept coming apart at the advertised 2800 fps limit.

I run a 1/6 for testing bullets and can assure you there are plenty of bullets that I can get flying sideways.

[iplaywithnoshoes]

The only situation which would not benefit from faster-than-normal twist would be precision, long range shooting. A faster twist can magnify the imbalance which is inherent to bullet eccentricity. The bullet can sometimes yaw as a result and give pooraccuracy. In this case, the slowest twist possible for the velocity achieved is the rule of thumb.

For 300BLK though, where few of us shoot past 300 yards, even in supersonic, a faster twist is more versatile than a slower one typically. I have had good luck with 150gr., 208gr. and 245gr. cast pills. (Super, Sub, Sub) Hoping to try the 125gr ones soon.

shoe

The fastest .300bo loads don't have enough velocity to over stabilize.

Overstabilization is a flight path characteristic where the bullet direction is no longer tangent to it's predicted flight path. The phenomenon i'm talking about is rotational imbalance which induces instability in flight. If you take two bullets with the same deviation in center of mass with regards to the bore axis, and spin them at different speeds, the bullet spinning faster will experience a more violent yaw or tumbling at sufficient speeds (like an imperfect spiral with a football). With subsonic loads, this is not a concern but with supersonic loads in the 110gr to 125gr range at around 2200-2400fps, your stability can be adversely affected if the bullets are not absolutely balanced to within microns of eccentricity. The math needed to verify the correct twist rate for your intended velocity and bullet LENGTH is quite easy and there are a few online calculators out there.

This is why I don't complain too much that my 1:12 twist Remington 700 .308 can't stabilize anything above 168gr SMK. Out to 700 yards, I know the bullet is quite happy at 2800fps out the muzzle.

shoe

[45r]

My rem 700 shoots 1 inch at 100 with noe PC 247 bullets over 9.3 grains Imr 4227 but shot like sh_t with 110 vmax over 20 grains w296.
I was surprised by that.