35RMB to the forum.

In the 260 I would for sure go with the 1:8 barrel. With that you should be able to stabilize any of the 140s and lighter bullets and the 160gr round nose bullets as well if you ever get the desire to try that them.

I have a 6.5-284 with a 1:9 and have no problem stabilizing the 140 Bergers but my atarting load is a 150fps or more faster than the starting load for the 260.

2800fps is the magic number here when in comes to twist rate theory. For example 140gr A-Max which is 1.385" long and 0.264" diameter (duh).

Required twist rate on velocities above 2800: 9.1
Required twist rate on velocities below 2800: 7.5

http://en.wikipedia.org/wiki/George_Greenhill

Yup, sounds about right, Berger 140s the most accurate loads I have worked up yet are 2825 and 2980 for average velocities. Both shoot 5/8 inch groups at 200 yards. Last group with the faster one at 325 was 7/8 inch.

Thanks again for the info.
Actually, I see myself staying around 100-130grains thus the interest in the twist. Not to mention that every loading book I've checked uses a 1:9" twist for everything. My main concern is actually using Nosler 130 Accubonds or Hornady's 129 Interbonds. Since they tend to have a longer bearing surface. I wonder if a 1:9" will be enought to stabilized them.

Nosler Accubond 130gr, length = 1.320"

Required twist rate (under 2800fps): 7.9

So I guess I'll be better of with a 1:8" twist, Huh!

How about lighter 100grain bullets, is there such thing as over stability? I do own a 7mm-08 that is a tack driver with 130g speers and 140g Accubonds if more Huuumph is needed.

Thanks again Gents

You should be gtg on the lighter bullete as well.

I don't think you will have any problem with even the lightest .264 bullets in a 1-8 twist.