Thinking of buying a .22, and have some Qs

[SL1]

In looking at catalogs and load manuals for some of the 22 caliber centerfire cartridges, it seems odd to me that the .22-250 has a twist of 14:1 while the .223 has a standard twist of 12:1 and Ruger uses 9:1. This leaves the odd situation that the .233 can apparently stabilize heavier bullets than the larger-cased .22-250. That is particularly true for the Barnes copper bullets, which are long for their weight.

Is there some make of .22-250s that use a 9:1 or 8:1 twist instead of 14:1, or would I need to gt a custom barrel for heavy copper bullets?

SL1

 

[Randy 1911]

22-250 shooters generally are varmit hunters. Therefore, most of the bullets they are using are lightweight bullets (less then 50 grains). Where the 223 usually shoots a heavier bullets which needs a faster twist.

 

[Jim243]

The twist rate will depend on the length of the bullet. Since the only way to make a .223 heavier is to make it longer since it will still be a .223 bullet.(actually .224)

The army started out with a 1:14 twist in the 1960's using a 40 or 50 grain bullet. Today I believe they are using a 62 grain bullet with a 1:12 twist. I have two .223 rifles and both are 1:9 twists. One is an AR, so I am stuck with an OAL of 2.250 ( the width of the magazine) and limited to bullets that will seat to that OAL max. The other is a Savage Mod 11 and I go to 75 grain bullets with that gun since I have no OAL problem with it (internal mag).

With a 22-250 shooter, they are trying for long range on very small creatures and can use the speed of the lighter (shorter) bullet that would tear apart with a 1:9 twist rate.

It's a matter of the right tool for the right job. Both have their place.

Good Shooting and stay safe.
Jim

 

[joneb]

http://www.savagearms.com/firearms/models/
Savage uses a 1:12 twist for 22-250 rem

 

[Scorch]

For many years, standard twist rate for 22 caliber centerfires was 1:16" for lead black powder bullets or 1:14" for spitzer jacketed bullets. Part of this is due to the difficulty of making 22 caliber barrels, the other part is that there was no need for faster twist rates because the 22 centerfire rifle rounds were used by varmint hunters (small thin jacketed bullets at high velocities for flat trajectories) and by benchrest shooters (extreme accuracy). When OTC and long-range match target shooters started using 22 caliber rifles, the rules started to change.

Up until about 10 years ago, there were very few 22 caliber bullets over 60 gr available, about everybody shot 50, 52, 53, or 55 gr bullets. 22 caliber rifles were seldom used in long-range target shooting, long-range target shooters were shooting 7mm, 30 caliber and larger. Heavy 22 caliber bullets like 68 to 80 gr VLDs do not have a trajectory advantage over lighter bullets until about 600 yds where the light bullets have slowed down so much that they are dropping fast, so this was an area where the Garands and M1As ruled before the heavier 22 caliber bullets became available.

So, to address your original question, with the right twist you could stabilize heavier bullets in a 22-250 and use it for longe-range shooting like F-Class (I know a couple of guys who do). Long-range target shooting has changed drastically due to bullet design, and shooters are using slower, more accurate, almost benchrest-like rifles in many matches. Zak Smith is a long-range competitive shooter who regularly contributes on these forums, and he may weigh in with more info for you.

Today's 22 centerfire bullets are longer due to boattail and longer ogive designs, so they need tighter twists, but the first AR15 and M16 rifle had 1:14" twist barrels, later changed to 1:12" in the M16A1 because the military found that the M193 55gr FMJBT bullet would not stabilize well in cold, dense arctic air.

 

[impalacustom]

Another thing your forgetting is the faster you push the bullet the less twist you need. So if your loading heavier bullets for the 22-250 it will be moving them faster than the 223, and both could end up having the same rpm even though the 223 chambered barrel has a faster twist than the 22-250.

A lot of times with custom benchrest rifles you will use the minimum twist you can and pick up the rpm with the velocity as the more twist you use the more pressure you have.

 

[SL1]

"Lead-free" seems to be changing things.

The new solid copper and the sintered-core frangible bullets being introduced these days seem to be changing things, both because they are longer and also because they can hold together at higher rpms. Also, at least for the all-copper bullets, there is no jacket concentricity problem to contribute to inaccuracy as rpms are increased. Barnes manuals now list twist rates needed to stabilize their bullets in various cartridges. They say a 1:8 twist is needed for their 70 grain TSX, a 1:9 for their 62 grain TSX, and a 1:12 for their 53 and 45 grain bullets. So, for instance, a Ruger model 77 in .22-250 would only be able to use the 36 grain Varmint Grenades, and a Savage would be able to use only their bullets weighing 53 grains or less.

I understand that varminters and long-range target shooters would choose specific (and different) twist rates based on bullets specificly suited to their intended use. But, for a multi-purpose rifle, I am wondering where the most versatile twist rate falls. And, whether that is changing as "unleaded" bullets enter the picture.

Jim243, in your Savage model 11 with the 1:9 twist, you say you are stabilizing 75 grain bullets (presumably lead-core). Have you noticed any problems with accuracy when using light bullets like the 36 grain Varmint Grenades or the various 40 grain bullets in that rifle?

SL1