Well, time to throw in a bit of crit info. All data is taken with 657 Crit, 689 AP, 260 Det, 12% Crit rate.

No venom numbers:

100 Potency--246-271, 373-412
150 Potency--370-409, 562-621
Auto--221-244, 336-371

Venom numbers:

100 Potency--295-325, 447-494
150 Potency--444-490, 674-745
Auto--265-292, 403-445

The 100 potency venom numbers trouble me. 325.5/294.5 is exactly 21/19, so there's no 21/19 spread that should give only 295-325, because a 326 should be possible if it's 325.5, or a 294 if it's lower than 294.5.

Honestly, though, the rounding errors here drive me crazy, which is why for a while I was working on a 500 potency fully buffed range, but that's ridiculously hard to get a range for when you're looking at ~300 values in the crit range. I was able to get a full non-crit range of 1793-1982, with an incomplete crit range of 2729-3012. Even if we assume that 3012 is the cap (which there's some room for it not to be), that's a x1.519677 multiplier.