Adding to the list from Heavy, these are some he missed or are OOP
Self Propelled
Add to the list above, M7 Priest - 105mm - Ilateri, M8 - 75mm - Tamiya, M4A3 - 105mm - Tamiya and Academy (Academy is the better kit), M40 - 155mm gun - AFV, M41 - 155mm - CMK (resin), M52 - 105mm - Hobby Fan (resin), M55 - 8 inch - Revell/Renwal 1/32 scale OOP. No kits avalable M37 - 105mm - (M7 Priest on M24 chassis), M43 - 8 inch - (M40 with 8 inch replacing the 155mm), M44 - 155mm, M53 - 8 inch
Towed
Add to the list above, M65 - 280mm Atomic Annie - 1/32 scale,Renwal/Revell OOP
Missle
M667 - Lance - Hobby Fan (resin), M50 - Honest John - 1/40 scale, Adams & Life Like OOP, M398 - Lacrosse - 1/40 scale, Revell OOP, M38 - Little John - 1/40 scale, Revell OOP, M?? - Corporal - 1/32 scale, Revell OOP, M?? - Redstone - 1/48 scale??, Revell OOP. Not avalable in kits Pershing
This list (between Heavy and I) I think covers Field Artillery since WWII both cannon and missle. If anyone sees something we missed please let us know.
The only other items which some people add but are not truly field artillery are Recoiless Rifles, Anti Aircraft Artillery (though through the late sixties the were part of the FA branch) and Anti Tank Artillery. Those are for another list in another thread.
Hopefully this gives your enough to collect and build.
Rounds Complete!