jeepers, the stuff costs like 2 dollars a box, go buy as many different boxes as you can find. shoot it up, see what works best. Every gun is different, some like green boxes, some like red, some like white boxes and some like it all. See what YOUR gun likes best.
Finally, try real hard to find your wife a much better gun for self defense, as a .22 rimfire is NEVER the best option, if you love her, buy her something decent. My wife shoots a ltwt commander in .45 acp and has no trouble. My sister in law shoots a g19 and has no trouble with that either. My mom shoots an old m19 S&W, shes 83 and has no trouble with +P short barrel speers in her gun.
If your wife likes the p22, try a p99 in 9 mm for her to try, same feel, just bigger.
Finally, try real hard to find your wife a much better gun for self defense, as a .22 rimfire is NEVER the best option, if you love her, buy her something decent. My wife shoots a ltwt commander in .45 acp and has no trouble. My sister in law shoots a g19 and has no trouble with that either. My mom shoots an old m19 S&W, shes 83 and has no trouble with +P short barrel speers in her gun.
If your wife likes the p22, try a p99 in 9 mm for her to try, same feel, just bigger.