Actually Bugger, the 280 AI and the BW do not share the same base to shldr dimensions. Correct one ate as follows.
280 AI base to shldr = 2.097
280 AI shoulder diameter. is.455
Gibbs base to shldr=2.1497
Gibbs shldr=.455
BW base to shldr=2.1266
BW shldr Dia. =.462.
A lot of smith's will just run a 35 Whelen AI reamer in to the depth of the BW shldr and call it a Brown-Whelen but it's not. If you don't believe me JGS in Oregon has the original prints.
Last edited by archeratlrg; 12/15/22.
