Pete Wass and I have the same mutual friend, and I was there at the Worlds when he did his testing. He tried three different lots with two showing no hope, but the third being absolutely "killer" ammo, so naturally he bought a full case of that "killer" ammo. Made sense at the time. Only problem was, it was 108° on the day he tested those lots, so when he returned back to reality that killer ammo turned out to be a full case of $1200+ carp ammo, and those other two lots, which he had less than a box each of after ruling them out, were where he should have spent his money. Case in point: the first match he attended after returning home he let another shooter borrow one of his guns, gave him what was left of the rejected test lots to shoot, and the fellow immediately turned around and shot a 250 with it.
Living in the northeast I have always been an advocate for not testing ammo during the dead of winter, or even during the early spring or late fall. Once the temperature drops below 50°, speed will drop so much that you won't get anywhere near the results of what you'll see once summer comes. Even though it makes prefect sense to test ammo at around the same temperature range as you'll be competing with it, I had no idea the same variance would hold true when temps skyrocket above 100°. So, now I would hold the line on only testing when the temps are between 55 and 85° as that is where we are during the majority of our shooting season.
Have you ever considered airguns? Top-of-the-line ammo will cost you less than $10.00 for a tin of pellets (500) and will mean that you and a couple of friends can sit down for an entire afternoon of shooting, and you'll still have enough left over for a match or two. Plus, if you drop a pellet, so what! They cost less than .02¢ each, and not the .25¢ - 40¢, or more, that rimfire has climbed to. Just a thought.
Dave Shattuck