Gibbs cartridge development dates?

I am trying to ascertain the development dates for the cartridges designed by George Gibbs and am having a great deal of trouble. Any help would be greatly appreciated!!!


Can’t help with dates but you have two Gibbs mixed up here. One is US & I think his name was Rocky & the British gentleman was George W - 360 #3, 461’s, 505, & 256 Mag.

edited to remove the 240.

What I have in my notes is that all your unknowns are circa 1954/1955 except 360 Gibbs no 3 which was circa: 1884.

Thanks Pete and Curtis. Good catch on the Rocky vs. George Gibbs, that really would have messed up my display, especially since they were made in different centuries!

Your newer Gibbs made by Rocky were largely wild cats based upon the .30-06 cartridge.

Thanks guys. Here is what I have for my display: