The 2000 lb GP Bomb AN-M66A2 has a cylindrical metal case, an ogival nose, and a tapered aft end. A box-type fin assembly is secured to the aft end of the bomb with a fin locknut.
The bomb accommodates a nose and a tail fuze, both of which are used for the majority of bombing operations. The bomb has an adapter-booster capable of receiving tail fuzes with a 2-inch thread diameter. A fuze adapter may be inserted into the adapter- booster to accommodate smaller fuzes with iy2-inch diameter threads.
Special studs attached to the base plug and imbedded in the solidified explosive filler prevent removal of the base plug. The adapter-booster (and fuze adapter, when used) are locked to the base plug with a locking pin that extends from the adapter- booster to a groove in the base plug.
Approximately 50 percent of the complete weight of the bomb consists of explosive filler. Two suspension lugs are welded to the bomb case with 30 inches between centers. A single suspension lug is welded to the case on the opposite side at the center of gravity.
The bomb is painted olive drab; yellow color bands and black stenciled nomenclature identify the bomb and its high-explosive charge.
The AN-M66A2 and AN-M66A1 bombs contain antiwithdrawal pins in the base plug and an adapter-booster and fuze adapter that can be locked in place. The earlier AN-M66 bomb lacks these features.
The AN-M66A2 differs further from the AN-M66A1 and AN-M66 bombs by having a thicker and rounder nose. In the AN- M66A2 bomb, the ratio of explosive charge to total weight is approximately 50 percent as compared to an average weight ratio of 53 percent in the other two bombs.
The AN-M34 bomb, an earlier model of the 2000-lb GP Bomb, is similar to the AN-M66 but has an Adapter-Booster M102 which will accept only those fuzes with a 1-1/2 inch diameter thread.
The M34 is identified by the tail-base cap and two Army suspension lugs. The suspension lugs are 30 inches apart. The AN-M34 has the additional single suspension lug and the tail-base plug. The single lug is on the center of gravity 33.5 inches behind the nose. The AN-M66 can be distinguished by the M115 Adapter Booster, used to adapt Navy fuzes to Army bombs. US Bomb, 2000 lb GP, M34, AN-M34, AN-M66, AN-M66A1, AN-M66A2 (bulletpicker.com)