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Well, I got my new .22-250 and it's a great rifle! http://www.shootersforum.com/showthread.htm?t=64892
I was just sitting here thinking about which bullet weight I could go up to.

I measured it several times and each time I came up dang close to 1-13" Twist. It is an old Douglas barrel from 1966. Still shooting good, but I was thinking on maybe trying some 60-62 gr bullets. I know that the 1-12" is good for bullets up to 63 gr, so maybe the 1-13" is good for 60's?

Anyone have any suggesitons.
 

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Bullets fired from any rifled barrel become less stable with increased length, more stable with increased weight, and slightly more stable with increased muzzle velocity. The strength of the influence of length, weight, and muzzle velocity are in that order of importance. Typically, as bullets get heavier they get longer, and since length is the dominant influence, that will be the undoing of the barrel's ability to stabilize them. So if you have a heavy round nose bullet, which is a short shape for its weight, you can often find barrel twist rates that will stabilize it just fine, but that cannot stabilize a boattail pointed nose bullet of the same weight.

The common statement that a certain twist rate will handle bullets of a certain weight range carries the unstated assumption that the bullets of each weight have the same shape and construction. If you count only lead core jacketed flat base spitzers, or only lead core jacketed short boattail bullets, or only VLD shape bullets, the chances are you can go by weight alone.

If you want to check a particular bullet, go to the JBM ballistics calculator pages and scroll down the calculations to the stability estimator. There is a list of bullet lengths also available under "Lengths" on the top black menu bar on the page. Get the length and weight of the bullet you want to try in your barrel from that list. Go to the calculator and plug in the conditions and muzzle velocity you expect. The result will be the gyroscopic stability factor for the bullet. If it is 1.0 or higher, the bullet should not tumble. If it is lower it should be unstable. If it is 1.3 to 3.0, the bullet should do alright on accuracy. Best accuracy is usually obtained if the bullet has a stability factor of 1.4 to 1.7, though the most sources cite 1.5 as the best compromise.
 

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Your rate-of-twist of 1-12" or 1-13" should handle bullets up to 60 grains with no problem in your .22-250.
 

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The 13" twist will only handle a 60 grain bullet well if it is under about 0.8 inches in length. The Barnes 62 grain X-tac, for example, would be too long to be stabilized by it. So would even the Barnes 55 grain multi-purpose, though it gets closer to the margin.
 

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A few thoughts....

Unclenick said it all and...

most 22-250's have a twist rate of 1-14 and handle 50-55 gr bullets great...some 22 cals have 1-9 now to handle longer 62-70 plus gr bullets.

Way back when, I rechambered a Ruger 220 Swift 1-14 to 22-243 Middlested...it shot up to 60 gr Hornady SP's great...50 gr Noslers and Hornady VMax even better, but WOULD NOT shoot the 60 VMax worth a hoot or ANY bullets of that length or longer. It shot the stubby 70 gr Sierra Semi-pointed into nice tiny bugholes also.

The man/men who first developed the 22-243 way back then, found a 1-12 twist would stabilize 60-65 gr bullets of that era much better than the 1-14.

After I shot out one barrel messing around with the wrong bullets, I followed their advice and the next barrel was a 1-12...when that one ended I did a 1-9 and shot mostly the longer 65-75 gr bullets. I also thought hard about doing a 1-8 or even faster for some very long 80-90 gr, VERY high BC bullets...but I like HIVEL and my 6mm's could handle those bullets weights very well so I went back to a 1-12 and 50-60 gr Noslers...I get all the speed I want and the Nosler stays together much better...at least it gets to the target without disintegrating from high rotational velocity.

Today, I think it has been well established what size/lengh the different twists work best with and unless you want to keep re-inventing the wheel, pick the bullet that works best with the twist you have and be happy with it, you will spend more time in the field shooting varmints that on the range working on loads.

THE RIFLE WILL QUICKLY TELL YOU JUST WHICH BULLET IT LIKES...irregardless of the twist. A 1-13 twist Douglas in 1966...it might have been a special order...sort of a tweener...in between 1-12 and 1-14 for a special porpose...who knows.

Twist rates are not cast in stone, there is a range of rates usually for each caliber and rifle makers just picked something in the middle that worked well with what they thought would sell for the most part...today we have more choices and MUCH more knowledge.

I can tell you first hand that you will end up bald pulling your hair out and spend tons of money on components if you try to make a silk purse out of old Dobbins ear.

This is one area that using the status quo works very well.

The 22-250 was designed to get higher velocities out of 50 gr bullets and 1-14 twist and it does a great job there.

Luck
 

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Discussion Starter #6
Thanks guys. That is what I was thinking. I have a 220 swift and another 250 with 14 twist barrels so I was just surprised when I found this one to be ~ a 13 twist! I was hoping that I could shoot a little heavier bullet with this one for a little larger game. I have plenty of other calibers to choose from so it's not a big deal ether.

My 14 twist rifles shoot 45 gr Nosler BT's and Seirra 55 gr Blitzkings extremely well, so If all else fails I will shoot the Seirra's. I know how the pulling of the hair and spending money thing goes, although luckily I have only bought one box of bullets that did not stabilize correctly in one of my customs, so I guess I have been fortunate.

I am usually pretty keen on choosing the correct bullet/weight for my rifles, but I need to get into the calculator a little more. I guess I'm spoiled by my fiance's grandfather who is the old benchrest shooter/gunsmith as to a source for information about shooting, but I can't bother him all the time ether.

I have not looked too much into which bullet to use, but maybe I'll look into some Hornadys and some cheaper bullets for this one, because all my other rifles like to eat the more expensive ones!

Ether way, I'll figure it out and I'll let ya know what happens.
 

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Well, I got my new .22-250 and it's a great rifle! http://www.shootersforum.com/showthread.htm?t=64892
I was just sitting here thinking about which bullet weight I could go up to.

I measured it several times and each time I came up dang close to 1-13" Twist. It is an old Douglas barrel from 1966. Still shooting good, but I was thinking on maybe trying some 60-62 gr bullets. I know that the 1-12" is good for bullets up to 63 gr, so maybe the 1-13" is good for 60's?

Anyone have any suggesitons.
how do you measure the barrel for twist
 

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Take a cleaning rod with jag and patch. Start the jag/patch into barrel muzzle end. Place a piece of tape near the handle forming a flag. Mark rod with black magic marker at muzzle end. Watching the tape flag push rod into barrel until its rotates one revolution. Mark the rod again. Withdraw the cleaning rod from the barrel and measure between the two marks. This is the twist in inches. There are other variations based on this basic method so feel free to experiment.
 
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