First off, is the action bedded to the stock? If not, have it bedded and see how it runs. If it is, then there are a few areas to check over.
What was the round count on the rifle? If you are unsure of the round count prior to purchasing it, you should have it bore-scoped by a smith to see how the barrel looks. You can tell a lot from scoping a barrel, and the smith can tell you in just a few minutes if it needs to be replaced. The 22-250 is a bit hard on barrels, and once they start to go, they will throw fliers. A little farther, and they just stop grouping. Do this before anything else if you are unsure of the round count or if it has over 1500 rounds through it. It will probably last to 2500-3000 if it has a 1-12 twist, unless it has been through many extended strings of fire. If the previous owner was a varmint hunter, I would have it scoped. Some varmint hunters will keep shooting even after the barrel is excessively hot, which can ruin a barrel in short order.
You need to make sure you are holding the rifle exactly the same from shot to shot. If it changes, your POI will change as well.
Have a good look at the crown on the barrel. If it has even a slight ding or imperfection, it needs to be re-cut. Even a small defect in the crown will cause fliers.
Post the specs of your loads, ie: how far into/off the lands, neck tension, sizing method, etc. It may help spot an issue or someone may be able to make a helpful suggestion.
What are you using for rests, bipod or pedestal and are you using a rear bag?
There are just too many causes of fliers to list. I would go over what has been listed, especially round count and a possible scoping, checking the crown, and bedding. They are the easiest culprits to spot. Most others take a bit more to figure out.
Good luck, i hope it shoots well soon.
Kenny