Memo regarding ammunition and caliber for new TD’s

This memo (dated 1949-05-01) discusses pros and cons with sub-caliber APCR rounds, in particular with regards to the armament of new tank destroyers. The difference between squeeze-bore and sub-caliber sabot rounds are briefly discussed, with sub-caliber sabot rounds being considered superior. It is concluded that a 50 mm sub-caliber APCR round fired from a 75 mm gun has better penetration than a full-caliber 105 mm round, and with higher shell velocity to boot. The author recommends choosing a 75 mm gun.