6.5-284 Norma vs .30-378 Weatherby
A to-scale size comparison of the 6.5-284 Norma and the .30-378 Weatherby, drawn from SAAMI and C.I.P. cartridge dimensions and aligned at the case head.
6.5-284 Norma (left) beside .30-378 Weatherby (right), shown at the same scale.
The 6.5-284 Norma has an overall length of about 3.23″ with a 0.264″ bullet. The .30-378 Weatherby runs about 3.75″ on a 0.308″ bullet. That makes the .30-378 Weatherby about 1.2x the overall length of the 6.5-284 Norma. See the full reference for each: 6.5-284 Norma and .30-378 Weatherby.