105mm XM148 case

[Rrickoshae]

Good afternoon, I wonder if someone can tell me about this 105mm case. It’s marked 105mm XM148E3, dated 1962 and beside the primer is another circular disc set into the base. What was this case for, a tank? And what was the purpose of the thing set into the base?
many thanks as always

Dave

 

[HAZORD]

You should show a profile view of the case if you want an identification. XM preceding a U.S. Model number means experimental, or the first issue of the case. The E3 means it is the third design of the experimental case. The XM versions of the 105mm Tank cases were always brass. The 148 case is used specifically for HEAT projectiles with long tail boom and fins, and the APFSDS-T projectiles. It has the shortest primer of the three types of 105 tank cases. The projectiles go deep in the case. In 1962 Early Vietnam) it would have been a HEAT projectile.

The plug you see is so they could crimp the projo in the case, and then pour the propellant grains in from the base to get more powder in around the tail boom. You also see these plugs on 105RR cases for heat rounds.

 

[Rrickoshae]

Nice one, that answers everything. Many thanks

Dave