This past weekend I went down to Mt Airy, MD (close to Frederick) to shoot at the DIFTA match on Sunday. Now, keep in mind that I have taken my scope on and off several times over the winter and have not zero'd it in since.
After helping with the lines I get to the sight-in area and take a couple of shots at 10 yards on a clean target. Can't see where it's hitting at all. I finally see some dirt move WAY off and realize I can't possibly adjust the scope enough to compensate. At this point I'm ready to just go spend the day with family because I'm obviously not ready. Last ditch effort I pull out my hex tools and take the scope and mounts off. During this process I realize the front mount wasn't actually attached...it was sitting on top of the dovetail <argh!> Getting everything back together I am finally seeing the pellet and get things dialed in. I have just enough time to check 30 (zero) and 55 yards but not much else. Things seem to be OK and I've run out of time so I register and get ready to shoot.
I quickly realize that 30-55 is close enough, but any small kz between 10 and 20 is essentially a miss on one or both shots throughout the whole course. Something is off, but I have no idea what it is, so I shoot the rest of the course simply enjoying the day and having some good conversations with Mike Harris (DCFSA) who I'm squadded with and the fellows next to us, Paolo and Scott.
Afterwards I realized that I didn't even laser that the 30 and 55 were true.
SO, don't do what I just did...
Come prepared with your gun shooting where you want it -- having zero'd and verified the day before, or at least within the last week ESPECIALLY if you've done any adjustment to your gun. Having a last minute panic like I did is not a good start to the day. Sight-in should be a time to verify that you are shooting every target at the hold-over you expect.
You should have a routine for your sight-in. It's a good idea to bring out small targets for your 11, 12, 13, 14, 16, and 17 yard increments as that is where the most change in trajectory will be. And you can pretty much bet that there will be several close targets with small killzones. I typically have small index cards that I attach to popsicle sticks and put into the ground.
In the end I didn't do as well as I had hoped, but I was hoping for a miracle given that I really wasn't prepared for this match. It was great to see friends after the long winter and meet new people that became friends by the end of the match.