Have used 3031 in 223, 30-30, 308, 7mm-08, 7-30 Waters, and 350 Rem Mag.
In all of these 3031 is an okay powder. I think it is good in the 30-30, 7-30 waters case as it tends to be more efficient with that parent case. Perhaps it is just my perception too as 3031 has been the old standard in those cartridges. I have quite a bit of the powder and some older primers, thus when reloading components got hard to find it became my go-to for barrel break-in, load testing, plinking powder. It might be a hair dirtier especially when compared to newer powders but it gets the job done.
Specifically in the 223, I used 3031 for 50 and 55 grainers. Shot decent enough to load bunches for p-dogs and plinking. Dirties up a bolt gun pretty fast but shooting lots of rounds does it too.
In the 350, I used it to create some reduced recoil loads for deer. On the lighter end of loads, I got some hangfires and sooty cases but I think this had everything to do with the small amount of powder and the case size. Nonetheless, those reduced loads are good but h4895 would be better.