Late_Starter wrote:
Thanks for your comprehensive answer. I have the same rifle. I am waiting for my brass trimmer to arrive and when I get that I am going to do the load testing. I have the ADI manual, from that my first set of tests is going to be 42.5 gn to 43.5gn at 0.3 grain increments while watching for pressure signs. If I do not get anything promising in the first test I will then test up to the max load, watching for pressure signs. I am using Hornady brass. To start with am I using the standard 2.800" (71.12mm) COAL, but will look at moving closer to the lands if I cannot get good groups.
My load for the 100gn Sierra HP pills is 45.0gns of AR2208, which is the starting load, but gave me the best grouping.
45.0gns AR2208, CCI LRP200, and 2.685" COAL (a very short projectile).
I got a grouping of 14mm (Centre to centre) at 100m, which is pretty good, in my mind.
The grouping widened out a lot as I worked up the load, but there looked to be another node somewhere just over 45.5, that might have been getting close as well.
But, I didnt see the point in pursuing it further; 14mm was pretty awesome for what I wanted(a light varmint load).
Another point I'd make; became obvious when working through various batches of the same 120gn Vmax loading the past fortnight.
I find certain batches of brass seem to deliver more consistent groupings with this rifle.
I cant be certain that any one particular type of brass has been more inconsistent, but I have noticed a change in grouping, when I change batches.
[Something I havent noticed before; usually not often I'm firing off enough ammo to see this]
I suspect it's the slightly different case volumes, as a result of how it came to be 7mm-08 brass.
I have factory Norma 7mm-08 brass, ADI and Winchester brass formed into 7-08 from .243, and Federal, Hornady, and PPU brass formed from .308Win.
I spend a fair amount of time getting my cases as uniform as possible when forming them, and they are all multiple reloads in.
And I also do more QC on my reloads than is likely needed for hunting loads.
But I havent done any inside-neck trimming, so It's possible I have donuts in the ex-308 brass.
My suggestion, is that if you are dialing in a load that is starting to group well, it might be worthwhile to try the same load across all your different batches of brass?
[And maybe measure the average volume in each batch, to see how much they vary?.]
Just an idea for you.
I havent pursued this, but if I was likely to be using the rifle more, I'd look into it.
I'll be interested to see what results you get from your 120gn Vmax loads.