Michael Bane has an article on training with smallbore and “even airsoft guns.” I can tell you from personal experience that shooting air guns will make you a better all around shooter, and these days there’s a lot of air gun sports.  You have Action Airgun which use airsoft guns, and is a good substitute for IPSC/IDPA. You can even compete online with this.  You also have 10 meter competition.  Then you have what I do, which is air gun silhouette. All of them are worthwhile, and will translate to other types of shooting. Back to Michael:
The fundamentals teach us to how to control a firearm…as we add more recoil, nothing should change. In a personal defense situation, or even when the buzzer goes off in a match, you will likely not notice the recoil, the noise or the blast, and if your fundamentals are sound the bullet will go where you intended it to go.My experience has been that a shooter who goes back to his/her duty or competition gun after a session training with .22s discovers the more powerful gun has less recoil than before (especially if that shooter has practiced extensively with full power ammo in the primary gun). Of course, the recoil didn’t miraculously go away…rather, subcaliber practice (after appropriate visualization and dry-fire) has allowed the shooter’s attention to be focused on controlling the gun through the application of the fundamentals rather than becoming fixated on the recoil, noise and flash.
Yep. Due to the ammo shortage, and sky high prices, I am shooting larger caliber pistols hardly at all, and am shooting almost entirely smallbore and air pistols. When, on that rare occasion, I do go to the range to shoot the Glock, my groups are tighter than they’ve ever been. You also can’t beat range availability for air guns. If you have a basement, you have a range. You can shoot every day, and it costs pennies.