.223 Rem with 1-9 twist

oldrodder

oldrodder

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Question for those who reload .223 Rem. for a rifle with a 1-9" twist........what bullet weights will this twist rate stabilize?
I have bullets in 50 gr, 52 gr, 53 gr, 55 gr and 80 gr. Also have some home swaged 60 gr.
Thanks for your help,
 
I no longer have my 1 in 9" twist; but when I did, I had worked up a load using Nosler Custom Competition 69 grain BTHP's and WC735 powder. They were laser-gun accurate and worked very well on varmints and anything else I used them on.
 
I had a 9t Savage that shot the 75gr Amax well. Other 9t rifles were Rem700's and were fine with the stumpy 77gr Nosler HPBT.
 
I used to do some consulting work with Savage. I was pressuring them to switch from the standard 1:12 to a faster twist. I wanted 1:8

They thought 1:8 was too radical, but agreed to try 1:9. They sent me 20 prototype rifles to try. I throated the chambers a bit so they would take a 80 gr Sierra Match bullet. This was the bullet I wanted a Savage rifle to be able to shoot.

I tested in cold weather, because it takes more RPM to stabilize a bullet in cold weather. I found that the 1:9 barrels would shoot the 80s so long as the velocity was kept up - near max.

RPM is a function of twist and velocity. Velocity is a function of barrel length. I think the Savage barrels were 26". You did not mention the length of your barrel. If it is a 18" AR-15, you probably won't get enough velocity to stabilize a 80. The 77 or 75 might stabilize. For sure the 68 and 69 will.
 
My 1:9 20" Rem700 .223 has trouble with 72-75gr BTHP anything. They are just on the edge of working at max loads. I'll get 3 or 4 out of 5 that fly properly. The other 1 or 2 will go wherever they like. Why bother when 69gr SMK, TMK and BMB work like little laser beams of solid energy at 300-600m. Lighter BTHP bullets work fine as well but tend to get blown about by the wind a lot more. If you have a nice long 24+ inch barrel so that you can get the powder load and velocity high enough (3200fps+) then they might work for you. 80 gr swaged lead will fail miserably and probably be downright dangerous, filling the rifling with lead at velocities anywhere near what any of the above fly.
 
Ganderite said:
I used to do some consulting work with Savage. I was pressuring them to switch from the standard 1:12 to a faster twist. I wanted 1:8

They thought 1:8 was too radical, but agreed to try 1:9. They sent me 20 prototype rifles to try. I throated the chambers a bit so they would take a 80 gr Sierra Match bullet. This was the bullet I wanted a Savage rifle to be able to shoot.

I tested in cold weather, because it takes more RPM to stabilize a bullet in cold weather. I found that the 1:9 barrels would shoot the 80s so long as the velocity was kept up - near max.

RPM is a function of twist and velocity. Velocity is a function of barrel length. I think the Savage barrels were 26". You did not mention the length of your barrel. If it is a 18" AR-15, you probably won't get enough velocity to stabilize a 80. The 77 or 75 might stabilize. For sure the 68 and 69 will.
Click to expand...

My rifle is a CZ 527 Varmint....24" HB. I bought a bunch of 80 grs here a while back and I was hoping this rifle would stabilize them. I have no experience with .224" heavy bullets. I've always used 52-53 gr HP's in my 22-250's for over 45 years. The 5 22-250's that live with me are all 1-12" twist. There were no heavies back then that I knew of!!! The dummy round that I made up and chambers in the rifle is 2.405" long, has to be fed single shot. At this lenght, the bullet extends well past the base of the neck of the case. The gurus tell us that this condition will cause pressures to rise. Maybe best to avoid the 80 grainers and buy bullets recommended for this twist.
Thank you all for your advice, much appreciated!
 
rick357 said:
My 1:9 20" Rem700 .223 has trouble with 72-75gr BTHP anything. They are just on the edge of working at max loads. I'll get 3 or 4 out of 5 that fly properly. The other 1 or 2 will go wherever they like. Why bother when 69gr SMK, TMK and BMB work like little laser beams of solid energy at 300-600m. Lighter BTHP bullets work fine as well but tend to get blown about by the wind a lot more. If you have a nice long 24+ inch barrel so that you can get the powder load and velocity high enough (3200fps+) then they might work for you. 80 gr swaged lead will fail miserably and probably be downright dangerous, filling the rifling with lead at velocities anywhere near what any of the above fly.
Click to expand...

Rick,
When I mentioned swaged bullets in my 1st post, I meant swaged JACKETED bullets, made with commercial jackets and .22RF jackets. Sorry for the confusion!!!
 
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