1 in 9 twist in a 223, can I shoot lighter bullets accurately?
- Thread starter 243ME
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Squeeze
New member
I have two 1:8 twist AR uppers, that shoot 55 gr. bullets
into impressively small groups. About the only problem you
may have is very light jacket bullets may come apart, but
in the .223 Rem., one would really have to have the rounds
jacked up to get to the velocities that turn light jacketed
bullets into gray mist.
I have never had a problem with 40-55 gr Vmax, or Nosler BTs,
coming apart in an AR-15.
Squeeze
into impressively small groups. About the only problem you
may have is very light jacket bullets may come apart, but
in the .223 Rem., one would really have to have the rounds
jacked up to get to the velocities that turn light jacketed
bullets into gray mist.
I have never had a problem with 40-55 gr Vmax, or Nosler BTs,
coming apart in an AR-15.
Squeeze
NM Leon
New member
There is always an "optimum" twist/velocity combination for any particular length bullet (it's really length not weight).
Having said that, a slow twist will not stabilize longer (heavy) bullets, but a fast twist WILL stabilize short (light) bullets. Your accuracy might not be quite as good as if the twist was optimum, but should still be very good.
Leon
Having said that, a slow twist will not stabilize longer (heavy) bullets, but a fast twist WILL stabilize short (light) bullets. Your accuracy might not be quite as good as if the twist was optimum, but should still be very good.
Leon
DocCoyote
New member
Quote:
There is always an "optimum" twist/velocity combination for any particular length bullet (it's really length not weight).
Having said that, a slow twist will not stabilize longer (heavy) bullets, but a fast twist WILL stabilize short (light) bullets. Your accuracy might not be quite as good as if the twist was optimum, but should still be very good.
Leon
This sparks another question in my mind, pardon if I'm intruding on the post, but what is the effect of velocity? Does higher velocity stabilize a given bullet better than lower velocity in the same twist barrel? I believe it is the RPM of the spinning bullet that gives it's stability. The reason I ask is because most 1:14 22-250's will not stabilize a 60gr bullet, but mine will only with a maximal charge. At lower charges I don't get decent groups and some keyholing, but when I really push them, they shoot great. I believe this is due to a higher rotation RPM at higher velocities, can anyone confirm this or correct my theory? Thanks.
There is always an "optimum" twist/velocity combination for any particular length bullet (it's really length not weight).
Having said that, a slow twist will not stabilize longer (heavy) bullets, but a fast twist WILL stabilize short (light) bullets. Your accuracy might not be quite as good as if the twist was optimum, but should still be very good.
Leon
This sparks another question in my mind, pardon if I'm intruding on the post, but what is the effect of velocity? Does higher velocity stabilize a given bullet better than lower velocity in the same twist barrel? I believe it is the RPM of the spinning bullet that gives it's stability. The reason I ask is because most 1:14 22-250's will not stabilize a 60gr bullet, but mine will only with a maximal charge. At lower charges I don't get decent groups and some keyholing, but when I really push them, they shoot great. I believe this is due to a higher rotation RPM at higher velocities, can anyone confirm this or correct my theory? Thanks.
CatShooter
New member
Quote:
I believe this is due to a higher rotation RPM at higher velocities, can anyone confirm this or correct my theory? Thanks.
You are correct - it is the rotational speed that gives the bullet stability, too slow and groups open up, slower still and the bullets tumble... but "too fast" (there is no such thing), and the bullets shoot fine, until the rotational speed is so high that the bullets come apart.
.
I believe this is due to a higher rotation RPM at higher velocities, can anyone confirm this or correct my theory? Thanks.
You are correct - it is the rotational speed that gives the bullet stability, too slow and groups open up, slower still and the bullets tumble... but "too fast" (there is no such thing), and the bullets shoot fine, until the rotational speed is so high that the bullets come apart.
.
NM Leon
New member
Quote:
until the rotational speed is so high that the bullets come apart.
You probably won't be able to do it with a .223, but you can get blowups with a 22-250. You might have to really push some light bullets out of a 1:14 twist, but any faster twist will blow them up quite nicely without much trouble. It's kind of cool to watch (though not very productive).
Faster twist (and higher RPM) will also affect the performance of bullets, frangible bullets (V-Max etc) especially. Their "explosive" potential depends on the amount of retained energy the bullet has at impact and how quickly the energy is dissipated. A bullet with a much greater RPM will also have much more energy to shed (at a given velocity), and will be much more "explosive".
Leon
until the rotational speed is so high that the bullets come apart.
You probably won't be able to do it with a .223, but you can get blowups with a 22-250. You might have to really push some light bullets out of a 1:14 twist, but any faster twist will blow them up quite nicely without much trouble. It's kind of cool to watch (though not very productive).
Faster twist (and higher RPM) will also affect the performance of bullets, frangible bullets (V-Max etc) especially. Their "explosive" potential depends on the amount of retained energy the bullet has at impact and how quickly the energy is dissipated. A bullet with a much greater RPM will also have much more energy to shed (at a given velocity), and will be much more "explosive".
Leon
Jack Roberts
Moderator - Deceased
The more wear in a barrel, the sooner it will have bullet blowups. A 7" twist 223 barrel shot in across the course competition will usually start having blowups at 6-7000 rounds in the rapid fire stages.
Jack
Jack
stiff neck
New member
My 1:9 Savage 12FV shoots the 40 Vmax awesome, shoots the 69 SMKs awesome too.
Jay Johnson
New member
Have a Savage 12Fv 1 in 9 twist it shoots 40 Gr. bullets great.
Christopher
New member
My 1"in 9" Savage and AR-15 both shoot 50 grain bullets very accurately.
That is what the 1 in 9 twist is made for. I would think the very best accuracy would come from 45 to 55 grain bullets.
1 in 10 twist should shoot 40 to 50 or 55 grainers the best.
1 in 8 should do very well with 50 to 64 grain bullets and
1 in 7 twist rate barrels should do well with 55 to 70 grain bullets.
This is my opinion from the top of my head.
Does anyone agree or dis-agree?
1 in 10 twist should shoot 40 to 50 or 55 grainers the best.
1 in 8 should do very well with 50 to 64 grain bullets and
1 in 7 twist rate barrels should do well with 55 to 70 grain bullets.
This is my opinion from the top of my head.
Does anyone agree or dis-agree?
Jack Roberts
Moderator - Deceased
Quote:
That is what the 1 in 9 twist is made for. I would think the very best accuracy would come from 45 to 55 grain bullets.
1 in 10 twist should shoot 40 to 50 or 55 grainers the best.
1 in 8 should do very well with 50 to 64 grain bullets and
1 in 7 twist rate barrels should do well with 55 to 70 grain bullets.
This is my opinion from the top of my head.
Does anyone agree or dis-agree?
I have to disagree.
A 9" twist is the absolute best for the 69MK bullets but will usually shoot 50 to 70gr bullets just fine.
An 8.5" twist is good up to the 77gr bullets and marginal for the 80gr bullets. An 8" twist usually handles everything from 40 to 80gr. A 7" twist is only needed for the 90gr bullets which are not performing like they should and almost nobody is shooting them at long range any more.
Jack
That is what the 1 in 9 twist is made for. I would think the very best accuracy would come from 45 to 55 grain bullets.
1 in 10 twist should shoot 40 to 50 or 55 grainers the best.
1 in 8 should do very well with 50 to 64 grain bullets and
1 in 7 twist rate barrels should do well with 55 to 70 grain bullets.
This is my opinion from the top of my head.
Does anyone agree or dis-agree?
I have to disagree.
A 9" twist is the absolute best for the 69MK bullets but will usually shoot 50 to 70gr bullets just fine.
An 8.5" twist is good up to the 77gr bullets and marginal for the 80gr bullets. An 8" twist usually handles everything from 40 to 80gr. A 7" twist is only needed for the 90gr bullets which are not performing like they should and almost nobody is shooting them at long range any more.
Jack
