223 Twist rates

[mcwoodduck]

Is it the faster you spin the bullet Say 1:9 the heavier the slug you can shoot, as opposed to a 1:14 or 1:12?
Was playing on the CZ site and looking at a CZ 527 LUX and it has a 1:14 twist  How haevy of a bullet can I send with that slow of a twist?

[chutesnreloads]

You are correct....faster the twist,the longer the bullet can be and still stabilize.For 1:14 I'd stay under 64 grains.The faster twist does not mean you must shoot a longer/heavier bullet,only that you are able to.

[mcwoodduck]

Was thinking of shooting the 60 grain Nosler Partitions out of a 223 for pigs and deer and other larger medium game animals.

[chutesnreloads]

Those are good bullets but I've found the Sierra Gamekings are plenty tough more accurate in my rifle and half the price of the Noslers.They come in two versions of 55 grain and now a 65 grain that you may be able to use.

[Wyo. Coyote Hunter]

  Mc, all of my .22 caliber rifles are 1-14...I have shot 64 grain ww in all with ex. accuracy, but of course the Hornet...I have also used 70 grain Speer...they are a bit soft..I used the Nosler Part. in my .22-250, but never the .223...right now I am shooting 64 grain ww in the 223 for my turkey load..the accuracy is excellent.. I never shot a hog with a caliber this light, but have shot quite a bit of medium game with .22 caliber rifles...the only failure I had was with a 50 Blitz(not the Blitzking) in a .222..it broke up on a deers shoulder and a second shot though the lungs did it..These were small deer, not Wy. mulies.., BUT one of my old friends, now passed on, told me when the .222 first hit the market in the 50's he shot 11 bucks with his and factory ammo and open sights... BUT deer were thick as flies then, so gettin a perfect shot would not have been difficult...the 65 grain Serria BT may be a bit too long for the 1-14 twist...the 63, 64, and 70 grain bullets I used were semi-pointed, but they worked like a charm...now I am not sure I would do this again, but it did work...

[mcwoodduck]

Good to know,
 Thanks.
the Deer I was thinking about are small Under 150 pounds swamp seer of eastern NC.
and pigs of similar size. here in Northern CA.

[shot1]

I have killed hundreds of east NC deer. Yes a 223 with a tougher bullet like the Sierra game king or the nosler partition will kill them but the problem is will you find the deer after it is dead? That area is covered up with swamps and VERY THICK cut overs and unless you have a VERY GOOD blood trail you have to step on a deer to find it if you don't have a dog. With the 223 you may not get an exit and if you do it will be a small hole and those little holes don't let much blood out. If you don't kill a deer in it's tracks trailing it up is really tough. As I said I have killed hundreds of these deer when I helped control a big farm where my buddy and I had to kill 100 deer each year to control crop damage. We learned what calibers kill deer dead in their tracks. Best caliber I have ever used is the 25-06. They don't really get too far away to shoot and it just plain drops them in their tracks especially when you are using the 117 gr Sierra bullet at or a little over 3000 fps.

[mcwoodduck]

So far all the deer I have shot there are pretty mush bang flop.  The few that were not usually ran into the swamp for a few yards and then fish hooked to the nearest field.
I amazed one of my firends when he shot a doe with a revolver and it took off one way and I said i would help him find it and went 90 degrees from where the deer headed.  i knew that there was trail 50 yards away and that the deer would head there  to get into the field.  So I headed there and about tripped over the deer when I hit the trail.  I started to gut the deer and by the time I had it done here came my friends up the trail following the blood looking down. did not see me till they looked around to see why there was a gut pile next to the draining deer.

[Lloyd Smale]

the couple deer ive shot with 60 partitions all had exit wounds and a good blood trail on the couple that ran. I shoot them out of a 1 in 7 twist ar. I think it was Dee on here that coudlnt get them to stabilize in a 1-14 barrel though.

[.Dirty-.30]

Here is a chart I found posted somewhere, some time back that lists the recommened bullet lengths for twists in .224 caliber.

I've attached a SAAMI chart for the .224 diameter bullets.

0.355 to 0.368 1 in 25
0.369 to 0.384 1 in 24
0.385 to 0.401 1 in 23
0.402 to 0.420 1 in 22
0.421 to 0.440 1 in 21
0.441 to 0.463 1 in 20
0.464 to 0.488 1 in 19
0.489 to 0.516 1 in 18
0.517 to 0.547 1 in 17
0.548 to 0.582 1 in 16
0.583 to 0.622 1 in 15
0.623 to 0.669 1 in 14
0.670 to 0.722 1 in 13
0.723 to 0.785 1 in 12
0.786 to 0.860 1 in 11
 

What I don't understand is how speed changes this, say a .22 Hornet at 2600 to a .22-250 at 4000 fps. Can anybody tell me anything about how speed affects these twists? Can a bullet made for a certain twist be pushed too fast? Will it keyhole?

[PowPow]

...how speed affects these twists? Can a bullet made for a certain twist be pushed too fast? Will it keyhole?

Velocity (feet/sec) x 12"/foot x 60 sec/minute = (in/minute)

(in/minute) / twist = bullet RPM   ....the value for twist would be a whole number like 9 or 14.

The answer is a really large number, but it is for minute which is a long time compared to the total flight time of a bullet.

I would think there is a "sweet spot" rpm for the various construction methods of bullets.
On the high end of velocity, seems like there would be a "come apart" rpm; what might happen to a small bullet at a high velocity in a fast twist. On the low end, I think keyholing results from low rpm due to the cartridge's ability to accelerate a heavy bullet.

FWIW - having derived equations for various practical purposes, I think Greenhill presented his equation in a format that was useful back in slide rule days, rather than in a comprehensive format. But that's just my opinion.   

[helotaxi]

Speed increases the RPM but not nearly as much as the twist rate does.  Speed also increases the upset force, so the faster the bullet is going the faster it has to spin to remain stable.  The good news is that the increase in RPM usually more than offsets the additional upset force.

[pastorp]

I don't know about all the fancy formulars but I know my CZ 527 lux with 1/14 twist would stabelize a 55 gr bullet but shot larger groups than it did with a 45 gr bullet. 62gr bullets opened the groups even more. 

Regards,

[dks7895]

If you want to shoot heavier bullets, look for something in a 1:9 twist.  Like pastorp said...your groups will open up with heavier bullets because the are not spinning fast enough to stabilize.  My buddy has a Handi with 1:12 and it shoots 50gr HPs the best.  My Stevens 200 with 1:9 will shoot 50gr - 69gr.   

[mcwoodduck]

Thanks,
The other day I saw 55 Grain Lead free soft points.
I will try them in my 527 American and see how they shoot before adding another Open sighted 223 rifle.

[chutesnreloads]

That lead free bullet is going to be longer than a  bullet of the same weight of conventional construction.