Re: MARKSMANSHIP BASICS - How hard do you hold
#1 Do you control the rifle with both left and right hands?
Prone I use my non firing hand for the rear bag, with shooting sticks or offhand I will put my non firing hand on the forend.
#2 Do you vary the hold according to the caliber and weight of the rifle?
my firing hand on bolt guns only has the tips of my fingers touching the grip pulling in slightly, my thumb stays on the same side of the stock as my fingers. Certain AR rifles I will wrap my thumb and fully grab the pistol grip then twist slightly and pull in firmly. Im trying to consistently "tighten up" the fit of the two halves, but on Other AR's like my 18" match grade rifle its not necessary to twist and pull hard, so I use my bolt gun grip and just pull slightly. the one thing that will change alot is how much I load the bipod, that is very caliber and rifle weight dependant, not to mention the terrain dictates how hard I can load a bipod.
#3 Do you vary the hold depending on the field shooting position?
yes as described above
#4 Do you prefer vertical pistol grips vs curved grip design?
Pistol grips all the way