I don't know about all hollow base bullets, but I do know that the .45 ACP poly-coated Bear Creek 200gr hollow-base RN lead bullet has the same external measurements as there poly-coated 230gr non-hollow base lead RN bullet (it just looses the 30gr from having the hollow base).
What does that mean to the reloader/ ... Well, if you load the standard 230gr RN to a OAL of lets say 1.25" .... since the 200 gr hollow base RN has the same dimensions, you would also set it to the same OAL of 1.25"
The only thing that may change is the powder load ... a lighter bullet normally will be loaded with a slightly greater powder change that a heavier bullet.
Hope that helps just a little.
Last edited by Turbo6ta; January 26, 2013 at 12:34 AM.