I'm getting ready to test out "Mr Quigley" on some long range elk next week and have done a considerable amount of testing to prepare. I wanted to post the following, especially for some of you who may be just getting in to long range. I know that a lot of you already are aware of this, but the pics are pretty revealing. I will likely be shooting at approx. 1100 yards, and, as you know, everything MUST be calculated correctly for this to work. The subject here is "cold bore" vs a warmed up barrel which is what happens when all of us fire a group to zero. I have seen very few rifles which will group the same on the first shot as in follow up shots. Since most of us don't like shooting a warning shot to warm up the barrel, we must know where poi is at cold bore.
This is also crucial for follow up shots if necessary. This pic clearly shows the affect would be 5 1/2 to 6 inches difference at 1100 yards. My test was to zero dead on at 100yards by firing a 4 shot group and then shoot on consecutive mornings firing the cold bore shot at one bull and the follow up shot at another. I chose 9:00 a.m. so the sun angle would be the same. As you can see, the groups were good and repeatable, but 1/2 moa different. If I were to just go with my zero, my first cold bore shot at an elk at 1100 yards would be nearly 6" low. This alone would not cause a miss, but you can't start out with a 6" error with all the other variables. This was with my 30/375 S.I. and 208 SXR's fired at 3010 fps.