Richard, the 450NE3 1/4" is not the same case as the 45-120. Though they are the same length, the 450NE has a far larger powder capacity. The rim dia is much larger(.626"), as is the head of the cartridge over the web (.548"). With a powder capacity of 136.04 grs water.

While the 45-120 is a smaller case ecentually a long 45-70, with the only difference between them being the case length. The 45-120 has a rim dia of .597, and a head dia of .506, and a case capacity of 113.04 grs water.

The 45-120 is made from the 45 basic brass, but the 450NE is the parent case for the 450NE 3'1/4", and all the smaller rounds built on the 450 case like the 450/400NE 3", and 3 1/4". The 450#2 NE is made on the .500 base brass. The 450NE chambering reamer will clean out a 458 Win Mag chamber completely, while the 45-120 will not!