Can the cheek piece be adjusted without tools and if not, what is needed?
Can the rifle's bolt be removed without dropping the Cheekpiece?
Does it come with a mag?
Is the spigot removable?
I have multiple sets: use them on 243Win, 308Win, 6.5x47Lap, 284Win and 45-70Govt.
In some cases, with a 20moa rail.
They work well but return-to-zero after removal and refitting is not to be relied on (is it ever?) and make sure you use correct torque.
It goes without saying that you have to...
Did you look for DO63? It used to be identical to AA1680 (both made by Explosia) and the tubs I've got even have labels stating it's the same stuff. I use it with 25gr bullets (surprising velocities, without killing brass.)
I tried H322 but didn't get the accuracy or velocity of DO63 or Lil...
I guess he could do a (statistical) power calculation and use it to determine how many groups he needs to shoot to detect a statistically significant difference between load recipes but personally I don't have the time to do this or the multiple shoots to try it!
I think you're identified the trap that many fall into: excessive development and change. This produces a lot of data, but usually of poor quality (see statistical significance, above in this thread and in the Precision rifle blog that Ben linked.)
Don't forget that the throat erodes during...
I doubt you'd notice even if there is. The Evo is a more modern design but the P12 us bigger. For the small powder charge of the 204Ruger, I doubt the extra space in the P12 will make much difference.