Rate of twist

[PA BEN]

I have a Winchester Mod.70 ranger youth in 7mm-08. How can I find what the rate of twist it has?

[Bofire]

You can use a rotating cleaning rod, put a bore brush on it, mark it with a  felt pen shove the brush in all the way, and pull it out for one full rotation and measure the rod to see how far it took for a full rotation. A full rotation in 8 inches is an 8 inch twist.
Carl

[addicted]

looks like all of their current modesl that come in 7mm08 have a 1:9.5 twist. not for sure what you have... but its pretty likely

[PA BEN]

Thanks, gave it a try and came up w/1:9.5

[PA BEN]

So what does the rate of twist have to do w/powder and bullet wt? And is the chamber part of the barrel length? Or does it start at the riffling?

[Nape.257]

The faster the twist the heaver the bullet you can shoot. A 1-9.5twist is faster than a 1-11twist. Most 7mm RemMag's are a 1-9twist and can stabilise bullets up to a 180gr bullet.

Your 7mm-08 holds less powder than a 7mm RemMag's so it will shoot slower and probably wont stabilise anything much over 160gr's.

Yes the chamber is part of the barrel lenght.

[addicted]

http://www.riflebarrels.com/products/caliber_twist_rates.htm

scroll down to the bottom chart for general caliber/weight to rate of twist specs. there are many charts like this.