A multi based on the M114A2 Howitzer.
This weapon saw service in the US Army in WWII, Korea and Vietnam before being replaced by the M198 Howitzer. It fired a bullet that is 6 inches in diameter and roughly 3 feet long and weighing close to 100 pounds!!!
The NH Army National Guard had these Howitzers until the M198 rolled out and these were replaced.
Ok, on to this cache.... as with any military item, there is a data plate. Your task is to locate said data plate to get some numbers to solve for the final.
The final is located at-
B=1st digit of the serial number
I=Last digit of the weight
G=10th digit of the NSN (National Stock Number)
H=6th digit of NSN
O=Number of the month this was made.
W= Last digit of the serial number
N43 46.BIG
W71.41.HOW