I have a quick question regarding reloading.
I was at the reloading bench last night making up some .243 ammo. I have worked up a recipe for it using 100gn (Speer) heads with an C.O.A.L of 2.339. So I loaded the new rounds to the same recipe as the last, but when I went to test them today I found that they would not chamber. when I removed to the round the head was marked suggesting it was hard up against the lands. So I measured the distance to the lands again with the new heads and found a C.O.A.L of 2.315.
So first question: Is this simply due to a different batch of heads or have I done something wrong? Second: I usually back off 20thou from the lands which gives me a good grouping at 300yds, so I assume that if I do the same the results should be the same regardless of the different length?
Any advice would be great