.223 barrel twist

jigger08

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Will a 1:12 barrel stabilize 75gr.bullets.Or,how heavy of a bullet can this barrel stabilize out to 500yds.
 
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sorry about the slight hijacking, but what happens when you put a high rate of twist on a light bullet? (1:8 with a 55gr for example)
what does the "overstabilization" do?
 
BlastingChipmunk said:
sorry about the slight hijacking, but what happens when you put a high rate of twist on a light bullet? (1:8 with a 55gr for example)
what does the "overstabilization" do?

It'll work just fine. That's why I look for fast barrel twists (1:8 or tighter). They will work with bullets from 45gr to 80gr just fine. A 1:12 limits you to 55gr and under. Over-stabilizing a bullet doesn't seem to affect accuracy very much. My Colt AR15 with 1:7 twist shoots nice tight groups with either 55gr bullets or 75gr bulets or anything in between :dancingbanana: BTW, the fast twist may spin thin jacketed light bullets fast enough that the jacket comes apart. That's why you hear sometimes that overstablizing light bullets affect accuracy. This usually happens with light bullets meant for the .22 Hornet.
 
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BlastingChipmunk said:
what does the "overstabilization" do?

Basically the bullet is spinning so fast the gyroscopic effect will not allow the angle of the bullet to follow the curvature of its flight path... ie it will fly 'nose up' more the further it travels... resulting in excess drag and inaccuracy. And that's assuming your bullet stays together. Some light varmit rounds will blow apart due to spinning forces. Not the best explanation I admit, but I tried.
 
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Can be done using a cleaning rod and brush

How do you do that?
__________________

Push a cleaning rod and brush to the muzzle but not out.

Mark the top of the rod where it exists at the back of the receiver.

Pull the rod back until the mark does one complete turn and is back on top.

Measure from the mark you made to the back of the receiver where the mark was made, this is the inches of twist, as your rod has made one revolution in this distance.

Hope i've explained this clearly.:confused: ;)
 
Don't overlook the 60 gr. varmint bulets out there. I've had very good success w/ 60 gr. Vmax over a charge of varget, out of a 1-12" remington tube.
Look slike a good rundown on finding the rate of twist Liberty. I have always done it pushing the rod, but I think pulling it back through would make things much easier!
 
Well, Gentlemen, my 1:14 twist Sako 222 will stabilize 64 gr Win Power Points and Speer 70 gr bullets. :cool:

It is a well established fact that it is not the weight that is the critical factor, it is the length of the bullet.

Ted
 
I read this in a book that I am reading about rifle accuracy. By douglas arnold.

you need a caliper for this.

Greenhill formula

Step 1) bullet length divided by bullet diameter = divedend #1

Step 2) 150 divided by divedend #1 = dividend #2

Step 3) dividend #2 multiply by bullet diameter = twist rate


example = .243 that is 1.075" long

so

1.075/.243= 4.4238683

150/4.4238683= 33.906976

33.906976 x .243= 8.2393951 or 8.23 or 1:8 twist


any questions?
 
Why not? said:
Well, Gentlemen, my 1:14 twist Sako 222 will stabilize 64 gr Win Power Points and Speer 70 gr bullets. :cool:

It is a well established fact that it is not the weight that is the critical factor, it is the length of the bullet.

Ted

You're right of course, but then so is everyone else. For a given caliber, the heavier the bullet is, the longer it is, provided the ogive is more or less the same. BTW, I also have a Sako (Vixen) in .222Rem. However, anything over 55gr doesn't seem to work in mine, groups really start to open up with the heavier bullets. How fast are your 62gr and 70gr loads?
 
RifleDude said:
You're right of course, but then so is everyone else. For a given caliber, the heavier the bullet is, the longer it is, provided the ogive is more or less the same. BTW, I also have a Sako (Vixen) in .222Rem. However, anything over 55gr doesn't seem to work in mine, groups really start to open up with the heavier bullets. How fast are your 62gr and 70gr loads?

That is the whole point of my post. You can have a heavy bullet that is considerably shorter than a lighter bullet in the same caliber.

In my old Sako L46, 64 gr (not 62) Power Points leave the muzzle at 2950 or thereabouts, the Speer 70 gr right at 2900 fps. :cool:

Ted
 
Ted has it right... it isn't just the weight but the length...

An old example of that is in a 12 twist 6mm. A 100 grain spitzter boattail will not stabilize while a 105 grain round nose will... the Hornady A-Max and V-Max bullets are also very long and require more twist than shorter bullets of the same weight.
 
223

I have a 1:9 twist Rem700P I cannot stabalize Hornady Amax 75gn, but I can do a great job on SMK 77gn. The Amax bullets have a long polymer tip and I am unable to stabalize them, the 77gn SMK's are actually shorter and I can get great groups with these.

I doubt you will get the 75's to stabalize in a 1:12 twist rifle.
 
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