I haven't seen one, but it's simple enough to measure some yourself. An optical comparator might be a better option, but a simple dial caliper can do the trick if you have a light touch. I'm sure they will vary a bit from lot to lot.
eyesopen, I don't know of any such website. With American "tapered" hulls you have to be careful which wad you use. The STS hulls have the most "taper". The Remington wads designed for this hull (TGT-12 & Fig-8) have .690" base diameters.
AA hulls are between STS and GM hulls in "taper", but closer to STS. Almost any WW designed for the AA hull can be used in an STS hull, and vice-versa.
GM hulls are only slightly tapered, and so are the Federal wads designed for use in them. The degree of taper is so small that you can use any of the European wads designed for Reifenhauser hulls. You can use the 12S0 wad in an STS hull for light 7/8oz loads. It will make a ring around the outside of the hull where the base of the wad expanded the hull. This wad in the new AA often hangs up on the ridge formed where the base wad and hull meet and curls the lip of the wad's base under. I don't use wads designed for the STS and AA hulls in a GM hull because of powder migration problems.
Reifenhauser hulls are straight-walled. The only thing you have to pay attention to is base wad height. European wads designed for these hulls range form .725" wad base diameters (Gualandi) and .729" ( Baschiere & Pellagri). Federal wads also work well in these hulls.
Reloading is simpler and results are better if you divide everything into two classes. STS and AA hulls go in one class. Gold Medal, Fiocchi and the European Reifenhauser hulls go in the other. Use wads specifically designed for STS or AA hulls in these two hulls. Use wads designed for GM hulls in the other hulls. While several of the European wads are truly superb, they are extremely expensive. You will find, as I have on numerous occasions, you get the same level of performance using Federal wads in these hulls, for considerably less money.