I realize the usual adage is 'don't shoot another's reloads'. Yes, that's accurate much of the time. I don't feel like buying unknown reloads at the gunshow.
On the other hand, if the loads are from a relative or known source, experienced reloader, I may well proceed with precautions. I normally would like to know the recipe, power, charge weight & bullet weight. I may then take a few apart, weigh the powder, adjust if needed.
Back to the OP'er's question, 30.5 grains of powder for 'most' 22-250 loads is on the lighter side. Most any pistol powder is ball or flake, yes, could be IMR-3031.
If you do shoot a few, testing with the chronograph is a good step.