Aussie,
You are really close in my opinion.
1) If you don't already have your Stiller, have them melonite the bolt for you. Tell Russ or Jerry I said HI.
2) I prefer the new McM A3/5 with sporter fill and the integral cheekpiece. The saddle cheekpiece is not adjustable for cast off and makes it very hard to get right behind the scope comfortably. There is about a 10 ounce difference between sniper fill and sporter fill with the A series. If you weren't using a brake, I would strongly recommend sniper fill but with a brake, the sporter fill is fine.
3) Consider either a 25" or 27" tube. I don't know why but the odd lengths seem to shoot better. Anything longer is not as maneuverable in a hunting environment.
4) I strongly recommend that you consider the Center Shot Products Muscle Brake. I met Jim See at the VHA shoot in South Dakota this summer and picked up one of his brakes for my tactical 260. All I can say is "UNBELIEVEABLE". I've got or tried virtually every brake out there and for heavy hitters with large contour barrels, this is the way to go. If you don't like the looks of the Muscle, consider a Shrewd Varmint Brake. It has 7 degree forward ports, can be contoured to your barrel and has no ports on the bottom or top so good for prone. I've got a light weight 338 Win Mag with one of these and it works well.
5) Install flush cups on the bottom and the left side of the stock and buy a TAB Gear Sling from Rifles Only with flush cup swivels. This is the most versatile carry setup out there. Carry the rifle muzzle up or down on your right shoulder, or muzzle down across your back or front. The quick release clasps allow you to quickly go to gun and the sling has a built in loop for slinging up as well as a built in stiff section in the rear for a hasty rear support when prone. Works like a champ.
6) Consider the NF 5.5-22x56. I own and have extensive experience with the 3.5-15, 5.5-22x50 and the 5.5-22x56. Forget the weight difference - it's an ounce or two at the most. For scoring animals on the hoof and precision shot placement out long the 5.5-22x56 is the way to go. Much better long range resolution with the 56mm objective. I prefer the MLR reticle with .10 mil knobs and zero stop.
7) You didn't mention bottom metal. HS Precision or Badger or both good. Personal preference. The HS 3 round (really 2 with a magnum) fits flush and they offer a 10 round. The Badger weighs a little more but will take a beating and uses AI mags.
Best Wishes and let us know how it turns out.
