Gene:
I have a question about one of the things you wrote (I've read about half the thread) and I would be very grateful if you could tell me if I have it incorrectly.
In post #85 you wrote
Quote#1
"Expressed in terms of ambient temperature and again, assuming we do nothing to compensate, the rifle will go out of tune completely with an increase of 20 degrees F and come back into tune with another 20 degree increase."
That caught my eye, because I had been following a belief that TEN degrees put a rifle from full tune to out of tune, based on THIS quote from an article I got off a British shooting club's site, entitled "PPC Load Tuning Tips – by Gene Beggs"
http://benchrest.netfirms.com/Standard Cartridges.htm
"If the rifle is in tune and shooting dots at 27 grains, it will begin to show vertical at 27.3 grains and will be completely out of tune at 27.6 grains...... Since temperature is the main reason for changes in DA you can accomplish the same thing by using only a thermometer. The ratio is .3 grains per five degrees F" [implying that 10 degrees would put the rifle off by 0.6 grains -- or fully out of tune based on the first sentence I quoted....]
Am I completely confused here? Is the difference between tune and out-of-tune 10 or is it 20 degrees? Quote #1 says 20, and if I am reading it correctly, Quote #2 implies 10! Or is it 1.2 grains to be out of tune, instead of 0.6?
The reason I ask is that the combination of (me and my rifle) are not yet accurate enough to be able to figure it out ourselves, but it would help me reduce ONE of my many errors if I knew roughly what to expect to change the load by for a 10 degree range. So I'm really asking a real question, not trying to give you a hard time or anything!
THANKS!
Gordon