Twist rates in 224

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Twist rates in 224

Post by andym79 » 15 Jan 2019, 8:14 pm

Hi guys, nearly or my shooting is done in bigger calibres with lead.

Jacketed shooting whilst not new as such kind if is to me. I normally try and go for the slowest twist I can get away with.

Anyway I am having a rifle re barreled with a 224 barrel and want to be able to use 55gr sierra super roos and maybe 63gr game kings. I have run through a lot of online twist calculators and they suggest that a 1:12 twist is too slow or marginal at best.! As I said, I like to go on the slow side generally, but don't want keyholing.

Does anyone shoot either of the two bullets above with success out of a 1:12 or do I need a 1:10?

I know 1:12 is common outside the 223 rem, so not everyone shooting 50 gr or less are they?

The velocity will be between 2600-2900fps, I reckon the low end for 63grs and the high for 55grs so not 22-250 or swift speeds. Shooting will be between 100-300 yards.

Thanks in advance
Last edited by andym79 on 15 Jan 2019, 8:44 pm, edited 1 time in total.
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Re: Twist rates in 224

Post by SCJ429 » 15 Jan 2019, 8:38 pm

You should be able to shoot both out of a 1:12 but your velocity is a bit slow. What case are you planning on using?

To be on the safe side you may have to try 1:10 but that will probably spin the lighter bullets more than required. Since you are planning on shooting Super Roo projectiles you are not looking for every last bit of accuracy so the extra rpm will help the bullet expand when it hits something.
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Re: Twist rates in 224

Post by AZZA'S HJ47 » 15 Jan 2019, 11:05 pm

I run a t3x super varmint 1-8 twist i predominantly shoot 69g pills with this rifle. However i shoot the super roos when out on the farm. At the range i have consistently shot under a inch @ 200 with my own blend.
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Re: Twist rates in 224

Post by duncan61 » 16 Jan 2019, 1:40 am

My .222 shoots 2800fps 50gn PSP well with a 1:14 twist .1:12 should stabilise 55 and 63 out of a .223
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Re: Twist rates in 224

Post by marksman » 16 Jan 2019, 11:25 am

to be totally honest I would just go with an 8 twist as you can go up to 80gr projectiles if you decide to in the future, a 1 in 9" twist would work as well :drinks:
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Re: Twist rates in 224

Post by bladeracer » 16 Jan 2019, 3:42 pm

marksman wrote:to be totally honest I would just go with an 8 twist as you can go up to 80gr projectiles if you decide to in the future, a 1 in 9" twist would work as well :drinks:


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Re: Twist rates in 224

Post by SCJ429 » 16 Jan 2019, 6:01 pm

If the case can only move a 55 grain projectile at 2600 to 2900 fps then it is not going to be able to move an 80 projectile very fast. Move up to a 22 BR or at least a 223.
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Re: Twist rates in 224

Post by duncan61 » 16 Jan 2019, 9:25 pm

Can you have to much twist??
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Re: Twist rates in 224

Post by SCJ429 » 16 Jan 2019, 9:57 pm

Too much rpm can make a bullet fall apart. The slowest twist that stabilises your bullet will be the most accurate. PPC shooters generally use 1:14 twist rates.
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Re: Twist rates in 224

Post by duncan61 » 16 Jan 2019, 10:06 pm

Thank you for that.The small experience I have at the range was an elderly chap trying to shoot F-class with a .223 and 1:9 twist and he was using 80gn pills but I was sceptical his combo would make 800 metres and it did not.It may have been the shooter.Any one know of anyone who has used a .224 out to 1000
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Re: Twist rates in 224

Post by JimTom » 17 Jan 2019, 7:58 am

1000, that seems a bit of stretch to me for a .223, but I guess could be done in the right hands. Id be interested to hear if anyone is doing this successfully.
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Re: Twist rates in 224

Post by duncan61 » 17 Jan 2019, 8:48 am

He had a fancy set up and lots of people were interested in his rifle but at 800 it just sprayed them all over
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Re: Twist rates in 224

Post by SCJ429 » 17 Jan 2019, 7:28 pm

A 223 shooting 80 grain projectiles is about equal to a 308 shooting 155 grain. It is probably the best way to start shooting at 1000.
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Re: Twist rates in 224

Post by duncan61 » 17 Jan 2019, 9:14 pm

But will it make it
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Re: Twist rates in 224

Post by SCJ429 » 17 Jan 2019, 9:19 pm

Easily, it is doing over 1300 fps at 1000 so it is above the transonic zone. Wind drift is slightly better than the 155 308 pill.
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Re: Twist rates in 224

Post by duncan61 » 18 Jan 2019, 11:31 am

Makes sense.I maybe over doing it with 168 matchkings in 7 mm
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Re: Twist rates in 224

Post by SCJ429 » 18 Jan 2019, 12:20 pm

A 168 grain SMK from a 7mm RM has way better ballistics and significantly better resistance to wind drift. Shooting 30 rounds in competition takes far more discipline with your 7mm than the puny 223. Miss a wind change with the 223 or the 308 and you are left scratching your head wondering where the bullet went.
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Re: Twist rates in 224

Post by andym79 » 21 Jan 2019, 5:50 pm

So how much RPM is too much?

Relating to how much twist is too much at 50-300 yards not 1000, how slow can you spin it or fast depending before its too slow to buck the wind or too fast and affects accuracy?

Is a 1:8 too fast, would a 1:10 be better?
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