small to big in 1-9 twist

[conan32120]

I have a 1-9 twist in my AR and I've run 53 to 69 gr bullets thru it with good stability through out the range. Just curious as to what success others have had with bullets at the extremes. How small to how big with a 1-9 twist rate?

 

[Jerry M]

I have shot 50 grain to 77 grain bullets in my 1-9 twist rifle, with excellent results. 50 grain out to ~400 yards, 55 grain out to ~550 yards, 69 and 77 grain out to 600 yards.

Good Luck

 

[tark]

I don't know how heavy the tracer bullet is, but it sure is long! My AR is 1-9 and the tracer rounds do quite well. Point first out to a couple hundred yards at least. With good accuracy.

 

[someguy2800]

Mine would shoot the 69 grain sierra or 68 grain hornady bthp but not the 77 grain sierra or 75 grain hornady.

 

[Turkeytider]

I`ve not shot lighter than 55 grain, nor heavier than 68 grain. With OTM and hunting rounds ( Hornady, Barnes and Nosler ) in that range, very good performance. No real need to go heavier. Savage 110 Storm.

 

[lightman]

I've shot from 40 grains to 69 grains in my 1-9 twist rifles. Not an AR though. I usually stick with 50, 55 and 69 grain bullets. I have not tried anything heavier, mostly because my intended use does not need anything heavier.

 

[Varminterror]

Velocity matters, so barrel length matters. A 24” 1:9 223 is spinning faster than a 16” 1:8”, so what stabilizes in a longer bolt gun may not stabilize in a Carbine.

Stabilization also isn’t the only parameter for precision, nor is it the leading detractor for short range precision. “Optimally stabilized” is a different thing than “stabilized enough to fly tip forward, with a bit of yaw,” which is very different still from “tumbling in flight to the point of keyholing on target.”

I’ve shot as small as 40’s and 45’s and as heavy as 77’s and as long as 75 A-Max’s in 1:9” twist barrels.

 

[conan32120]

Velocity matters, so barrel length matters. A 24” 1:9 223 is spinning faster than a 16” 1:8”, so what stabilizes in a longer bolt gun may not stabilize in a Carbine.

Stabilization also isn’t the only parameter for precision, nor is it the leading detractor for short range precision. “Optimally stabilized” is a different thing than “stabilized enough to fly tip forward, with a bit of yaw,” which is very different still from “tumbling in flight to the point of keyholing on target.”

I’ve shot as small as 40’s and 45’s and as heavy as 77’s and as long as 75 A-Max’s in 1:9” twist barrels.

It never dawned on me till I read your post how a longer barrel (higher velocity) can have a faster rotation than a shorter barrel (lower velocity), that's perfectly logical and answers some unasked questions of mine. Kudos to you

 

[2ndtimer]

It never dawned on me till I read your post how a longer barrel (higher velocity) can have a faster rotation than a shorter barrel (lower velocity), that's perfectly logical and answers some unasked questions of mine. Kudos to you

It gets even more complicated. My 1 in 12” twist Remington 26” barrel will stabilize a long Hornady 62 gr BTHP with good accuracy at 100 yards in warm weather, but in freezing temperatures, they won’t stay on paper at that range. The fact that they are loaded with ball powder may also attribute to that effect, since my 40 gr bullet handloads with TAC powder lost 300 FPS at 30 degrees compared to same loads at 80 degrees. Haven’t chronographed the 62 gr loads at low temperatures yet.

 

[jak67429]

What varminter said, plus each barrel is a mystery onto itself. the2 ar's I use for prairie dogs are both 1-9 20"heavy barrels, both by the same barrel maker. 1 will shoot anything from 45 to 62gr. the other likes 55 to 70gr.

 

[someguy2800]

Bullet length is also a factor. You can have two bullets of the same weight, one long and pointy, and the other rounded and blunt, and you'll be able to stabalize one but not the other.

It gets even more complicated. My 1 in 12” twist Remington 26” barrel will stabilize a long Hornady 62 gr BTHP with good accuracy at 100 yards in warm weather, but in freezing temperatures, they won’t stay on paper at that range. The fact that they are loaded with ball powder may also attribute to that effect, since my 40 gr bullet handloads with TAC powder lost 300 FPS at 30 degrees compared to same loads at 80 degrees. Haven’t chronographed the 62 gr loads at low temperatures yet.

what primer where you using

 

[Archie]

Velocity matters, so barrel length matters. A 24” 1:9 223 is spinning faster than a 16” 1:8”, so what stabilizes in a longer bolt gun may not stabilize in a Carbine.

This can be deceptive. I had a .22-250 Remington with a 1:14 twist. It shot 55 grain bullets well. But it just would not stabilize 69 grain match type bullets worth a hoot. It would do better (but still poorly) with some 70 grain round nose bullets. The 70 grain bullets were just a trifle shorter.
I reasoned that shooting them faster would spin them faster and solve the problem. It doesn't.
From all the research I did the fast velocity produces more atmospheric resistance and therefore a greater tendency to yaw. Those were the symptoms I found and it seems to fit the explanation.

 

[Bfh_auto]

This can be deceptive. I had a .22-250 Remington with a 1:14 twist. It shot 55 grain bullets well. But it just would not stabilize 69 grain match type bullets worth a hoot. It would do better (but still poorly) with some 70 grain round nose bullets. The 70 grain bullets were just a trifle shorter.
I reasoned that shooting them faster would spin them faster and solve the problem. It doesn't.
From all the research I did the fast velocity produces more atmospheric resistance and therefore a greater tendency to yaw. Those were the symptoms I found and it seems to fit the explanation.

Going faster only helps if your twist rate is marginal. I couldn't even get a 1-12 22-250 to stabilize 69 grain bullets. Your 14 has no hope.
But pushing 77s hard in a 1-9 twist makes them hold accuracy better in my experience.

 

[2ndtimer]

Bullet length is also a factor. You can have two bullets of the same weight, one long and pointy, and the other rounded and blunt, and you'll be able to stabalize one but not the other.



what primer where you using

Remington 7 1/2’s

 

[Varminterror]

This can be deceptive. I had a .22-250 Remington with a 1:14 twist. It shot 55 grain bullets well. But it just would not stabilize 69 grain match type bullets worth a hoot. It would do better (but still poorly) with some 70 grain round nose bullets. The 70 grain bullets were just a trifle shorter.
I reasoned that shooting them faster would spin them faster and solve the problem. It doesn't.
From all the research I did the fast velocity produces more atmospheric resistance and therefore a greater tendency to yaw. Those were the symptoms I found and it seems to fit the explanation.

This is a story of a bullet which wasn’t spun sufficiently fast enough to be stabilized, which was then sped up, and still not sufficiently spun fast enough to be stabilized…

Sure, length of the bullet matters as much or more than the weight, that’s pretty simple.