I feel like your original questions are not fully answered….
Graybeard Classic said:
I've mentioned that I will be using a Vortex Crossfire 2 in 6-18x44 BDC Dead Hold scope, and I've been watching videos on using 1st and 2nd focal plane and that one of them will actually pull the reticle's mil mark slightly off true target while changing power. Now I'm no genius, but I need it in layman's terms on how to set it up and/or leave it alone, or am I just overthinking it?
SFP = Target gets bigger/smaller, reticle size fixed as power turned up/down. Reticle measurements good at one magnification level. See manual.
FFP - Target and reticle get bigger/smaller by same ratio as power turned up/down. Reticle measurements good across power range.
…..one of them will actually pull the reticle's mil mark slightly off true target while changing power….
That is wrong or a poor description.
With SFP, the reticle usually works at max power 18x. So, it is best to carry and shoot max point blank range style….no adjustment, or use turrets to adjust except on 18x where reticle and or turrets can be used.
Often times lower priced optics turrets can sight in but not reliably move to a new adjustment. Often times turning 1 moa past the new adjustment and back, then adjust to the planned adjustment can help. Then again, sometimes cheaper turrets blow up when adjusting too much. Vortex has a good warranty. Crank on them and hold Vortex accountable to a perfect adjustment through warranty.
I find 18x too much magnification for deer under ~500 yards, so maybe on deer the bdc is not helpful. It would be great on varmints.
Does that help?