.223 Remington Twist Rate?

2ndtimer · Apr 20, 2017

My experience with .223 Rem bullets and twist rates has always been with 1 in 12" twist bolt guns (26" Remington and 22" Weatherby Vanguard) and 1 in 8" AR's (24" Stag and 16" S&W original Sport with 5R barrel). I shot a lot of 40 gr through 55 gr bullets through the bolt guns without issue. They seemed to prefer the 40 and 50 gr bullets. The 1 in 8" AR's got more of the 55 gr bullets and some heavier bullets as well. I avoided the really thin jacketed bullets in the AR's (Hornady SX, Speer TNT) for fear of bullet destruction due to fast twist rate. Surprisingly, the 40 gr tipped bullets (Nosler Ballistic Tips, Hornady V-MAX and Z-MAX) shoot very well out of the AR's. I also avoided the heavier bullets in the 1 in 12" bolt guns, assuming the 69 gr bullets would but unstable and be tumbling at the target. At the range yesterday, I decided to try one of my 69 gr Nosler loads in the 26" 1 in 12" Remington just to see how inaccurate they would be. To my surprise, 5 shots at 100 yards grouped in less than .75 of an inch! Could this be attributed to the higher velocity provided by the 26" barrel allowing the longer bullet to stabilize? Any thoughts? That Remington 700 SPS Varmint shoots everything well, but I have never tried a bullet weighing more than 55 gr before, since "everyone knows you need at least a 1 in 9 twist for a 69 gr bullet in a .223".

HB of CJ · Apr 20, 2017

Probably just a combination of factors. I think one would have to drive the very thin jacket varmint bullets much faster before one experienced jacket separation employing the very fast big long bullet twist rates found out of an AR15. Just me.

DizzyJ · Apr 23, 2017

2ndtimer said:
My experience with .223 Rem bullets and twist rates has always been with 1 in 12" twist bolt guns (26" Remington and 22" Weatherby Vanguard) and 1 in 8" AR's (24" Stag and 16" S&W original Sport with 5R barrel). I shot a lot of 40 gr through 55 gr bullets through the bolt guns without issue. They seemed to prefer the 40 and 50 gr bullets. The 1 in 8" AR's got more of the 55 gr bullets and some heavier bullets as well. I avoided the really thin jacketed bullets in the AR's (Hornady SX, Speer TNT) for fear of bullet destruction due to fast twist rate. Surprisingly, the 40 gr tipped bullets (Nosler Ballistic Tips, Hornady V-MAX and Z-MAX) shoot very well out of the AR's. I also avoided the heavier bullets in the 1 in 12" bolt guns, assuming the 69 gr bullets would but unstable and be tumbling at the target. At the range yesterday, I decided to try one of my 69 gr Nosler loads in the 26" 1 in 12" Remington just to see how inaccurate they would be. To my surprise, 5 shots at 100 yards grouped in less than .75 of an inch! Could this be attributed to the higher velocity provided by the 26" barrel allowing the longer bullet to stabilize? Any thoughts? That Remington 700 SPS Varmint shoots everything well, but I have never tried a bullet weighing more than 55 gr before, since "everyone knows you need at least a 1 in 9 twist for a 69 gr bullet in a .223".

The twist rate guidelines are just as you have experienced:"guidelines".

Often times fast twist rates 1:7 will do very well with the lighter bullets, and heavier bullets can be accurate out of slower twists. Velocity has a lot do do with it. I suspect your faster velocity is making up for the slower twist rate in your longer barreled bolt guns. A real test would be to take those heavier bullets out to 300-400 yds and see if they're still stable.

I've got a Savage .223 bolt action with a 1:9 twist that can put three shots into one hole at 100 yds with Nosler 77gr custom comp bullets. It'll keep 1/2 MOA accuracy out to 600 yds as well, so I know they're stabilized.

It all boils down to your individual rifle.

Good job testing it for yourself. That's where true learning begins.

No_Regerts · Apr 23, 2017

DizzyJ said:
The twist rate guidelines are just as you have experienced:"guidelines".

Often times fast twist rates 1:7 will do very well with the lighter bullets, and heavier bullets can be accurate out of slower twists. Velocity has a lot do do with it. I suspect your faster velocity is making up for the slower twist rate in your longer barreled bolt guns. A real test would be to take those heavier bullets out to 300-400 yds and see if they're still stable.

I've got a Savage .223 bolt action with a 1:9 twist that can put three shots into one hole at 100 yds with Nosler 77gr custom comp bullets. It'll keep 1/2 MOA accuracy out to 600 yds as well, so I know they're stabilized.

It all boils down to your individual rifle.

Good job testing it for yourself. That's where true learning begins.

bsa1917hunter · Apr 23, 2017

I agree, that is a great posting. What you don't hear a lot about is bullet RPM or how fast you spin them. A while back I read an article about how some of the bench rest shooters calculate for bullet spin to attain the best shooting combination in their rifles. Here's a cool little article I found interesting:
Bullet RPM Calculator — Spin & Stability within AccurateShooter.com

I found out my .223rem rifle likes to spin them around 340,000 RPM..: