I like to use a lot of sources to. The hodgdon site used 13 powders with the 200 grain .308 and over 20 powders with the .30-06, and they saw a grand 70 fps from trying over 20 powders! That is every IMR Winchester and Hodgdon powder that applies to either round. That is far more choices than ANY other source. The common argument is that the .308 is useless with 200 grain bullets because it will only fling them at 2300 fps, but the .30-06 is much more useful shooting a 220 grain pill at 2300 fps? If you use a bullet like an A frame, no animal on the planet will no what they just got shot with. Do I have a dog in the fight? Kind of, because I found a .308 barrel for my KP1 before I found a .30-06 barrel. I would have been happy with either and I would take either hunting for anything in North America, but for the heavy bullets, I would much prefer a .300 Win Mag or a .300 H&H. If I wanted to shoot the heavy bullets with an 06, make it a .338!
How many test barrels did the Hodgdon site use for the 308 & for the 30-06, 1 each, 3 each, what. The fact that they used alot of powders is why I said it was a good source, but likely with a limited # of barrels used, & was either cal barrel a fat or slow barrel? That's why I don't use 1 source, if you look at the Hodgdon manual they will give
A TEST GUN used, just like the other manuals. The other manuals used not as many powders but used a mix of Hodgdon, Reliant, Win. & VIHTpowders with the optimal burning rates for the cartridges discussed, Hodgdon had redundancy showing all the powders regardless of burn rate because they are a powder company, the other manuals are bullet companies showing only the best powders of all brands with a given bullet.
So, looking at just a few which in total give a far more accurate picture than just looking at one powder company source with a test rifle:
Sierra Fifth shows a 250fps spread with the 200gr.
Hornady has a 190 gr & with it the spread shows 300fps (that is just as high a spread as the Hodgdon is low)
The New Nosler Manual does not even bother with the 200 in a 308, but has a page full of 200 gr. '06 loads, but shows a spread of 164fps with a 180.
The New Speer Manual shows a spread of 155fps with the 200gr.
Now these combined have alot more powders used by
ALL major brands, alot of different type bullets,
a heck of alot more powder used & a
FAR more accurate picture of reality. So, puuting it all together is the way to go. Anyone who has loaded both of these rounds alot as I have and see 50-70fps diff. with the 200gr. knows that something is alittle off.