Steyr Mann - 222 twist rate

[Farmer Rick]

Hi all, so I have a question someone might be able to help me with. I have a 1989 Steyr 222 varmint, and enquired direct with Steyr about the twist rate. Apparently it is a 1:9 twist, or 1 in 228.6mm.

I thought this was pretty high given the 222 cal and ask to double check but they say it was taken directly from the drawing... anyone know anything about this?

 

[Cottis]

I would say there is a staggeringly small chance of it being 1 in 9. The cartridge was designed sort of around the 50grain bullet and most barrels are 1 in 14 twist which suits most flat based bullets in that ball park.

I have a 1 in 10 twist .222rem but that is a more modern rifle and I expect is an exception to the rule in terms of off the shelf rifles.

Test it yourself (cleaning rod, marker on rod) and see what it is.

 

[Farmer Rick]

I can say the we adamant that they were correct! see attached. I agree I thought it strange, but it was a later development with the varmint barrel, so wondered if they did something different... will have a go with the rod.

 

[Cottis]

Fair, they would know more than me about their own barrels.

Stick some tape on a rod and whizz it down the bore with a tightish patch on and see what you get. Hopefully it is a faster twist, as they are more versatile.

 

[Ade8mm]

The varmint SL was deffo 1:14 in the early '70s. Maybe they changed the twist on later versions. As others have said above, it's easy to check with a cleaning rod.

 

[Farmer Rick]

Will give it a go and let you know the out come. Thanks for the help

 

[Farmer Rick]

Hi all, so I have some results, after trying to find the perfect patch thickness to grip but not over grip! I have repeated these around 10 times to be certain... and excluding some in tolerance’d measuring tape, a little friction in the system and general user error... it appears the Austria’s are in deed correct!!! From my measurement we are around 1:232mm vs their 228.6mm
I keep checking it, but seems they are a need correct and keep very good records!!!
I’ve just done it again.... and it’s right!!
The 2 photos are the 2 full revolutions over a 26” barrel

 

[Farmer Rick]

I can’t stop doing it, feels unbelievable, but the last attempt with a well rifled patch I would say has pretty much hit the mark exactly!!! Near as dam it 228.6mm!!! (Lowest marks obviously)

cleanest I think the gun has ever been

 

[Farmer Rick]

Has anyone got any advice or thoughts on the 1:9 twist?
It was interesting I ran some left over Sako varmint rounds through the rifle when I first got it, and it hated them, 2"+ groups. The Hornady V-max 50g it came with work pretty well with sub MOA - and close to 1/2". According to the marketing gumph, they are faster than standard 222 rounds, wondered if that helps combined with the twist rate?
I'm going to look at doing some load development, any inspiration on what might be good to compliment the 1:9, obviously I should be able to play with slight heavier bullets... Any thoughts, advice or ideas are welcome.

 

[Cottis]

You will certainly be able to stabilise bullets heavier than the standard fare which the .222rem has historically used but I doubt you need or want to shoot anything that heavy if you bought a .222rem. Anything in the 50grain area will shoot well but if you wanted to shoot 60's or even a touch more, it would probably shoot them well enough but only loading them up and testing will tell you for sure how they shoot.

What will you use the rifle for? You are in Scotland, so is this a rifle for Roe? If so, a heavier bullet that will do lesser speed than normal .222 rounds might well be a good idea. Something around 60grains would probably be good.

If you are using it to shoot foxes and pests, I would stick to the ballpark of 50 grains or so. You will maintain velocity north of 3000fps and enjoy destructive terminal performance assuming the correct frangible bullet is chosen.

I personally use 53grain Noser Varmegeddons in mine. They are a very accurate and destructive bullet. They also do a 55grain bullet which is easier to source. Vmax also work well. I personally would not go lighter than that as they get blown about by the wind a bit more when shootig over longer distances but that depends on your application I suppose.

 

[Farmer Rick]

You will certainly be able to stabilise bullets heavier than the standard fare which the .222rem has historically used but I doubt you need or want to shoot anything that heavy if you bought a .222rem. Anything in the 50grain area will shoot well but if you wanted to shoot 60's or even a touch more, it would probably shoot them well enough but only loading them up and testing will tell you for sure how they shoot.

What will you use the rifle for? You are in Scotland, so is this a rifle for Roe? If so, a heavier bullet that will do lesser speed than normal .222 rounds might well be a good idea. Something around 60grains would probably be good.

If you are using it to shoot foxes and pests, I would stick to the ballpark of 50 grains or so. You will maintain velocity north of 3000fps and enjoy destructive terminal performance assuming the correct frangible bullet is chosen.

I personally use 53grain Noser Varmegeddons in mine. They are a very accurate and destructive bullet. They also do a 55grain bullet which is easier to source. Vmax also work well. I personally would not go lighter than that as they get blown about by the wind a bit more when shootig over longer distances but that depends on your application I suppose.

Thanks for the reply Cottis, some great info there! the rifle is mainly for foxes, but the odd roe from time to time. I was thinking to stay sub 60g. The hornady vmax is working well factory at 50g, but I know they do a 53g in thier 223 factory and thought that bullet might be worth a try... with a nice powder it would be getting close to the 223 ballistics of other brands I think, ultimately I would just like to see how accurate the rifle could be with the right load, and what might be some variations to try as a starting point.