I remember when my son was going to qualify for his level 3 Security permit and he had to shoot a shotgun. He had bought one, but I had never owned one until after he was already grown, so he had never actually shot one. I could tell he was intimidated by it, and I only gave him one piece of advice - tuck that stock into your shoulder tight and leave it there until you're done pulling the trigger.
Shotgun recoil can be fun, as long as it's not overkill, I've never really cared for magnum 3'' loads because it's always seemed like there was plenty of takedown power in the regular loads. Sounds like you've gotten past your fear, and thats great.
The 3.5" 12s are only 3 T shot pellets short of a 10 gauge. You hold 'em up side by side, the 12 is nearly the same diameter. 12 gauge guns tend to be much lighter than 10 gauge guns, so the recoil is horrendous. I bought a Mossberg 535 with thoughts of goose hunting with it, but I stick with my single shot 9 lb H&R 10 gauge due to superior patterns and less recoil. That 535 weighs little more than my 500 duck guns and it flat sets you back.
But, goose hunting is where the 3.5" stuff is needed and, indeed, when Mossberg came out with the 835 it was prompted by failures of steel shot 3" BBB to cleanly kill geese at extended (over 30 yards) ranges. Snows are hard to get down, especially late season, in range of a 3" BBB load. Steel shot laws went into effect in 1980 in Texas. Now, one can shoot heavy shot and BB heavy shot works pretty well, but at $3.50 a shell, it ought to! I can get 25 rounds of 10 gauge T shot for the price of 10 rounds of 12 gauge heavy shot and I can halve that price with my MEC reloader.
I used to shoot 3" 2 or 3 steel 12 gauge on ducks. It ain't that hard on the shoulder, really. It's all in your perspective, but waterfowlers had better be up to the recoil or find another bird to hunt.
Now days, though, I find 2 3/4" fasteel, Kent first started loading this stuff back around 2000, to be superior to the old 3" stuff I used to shoot. Fasteel has less shot and more velocity and it does reach out there and tag 'em at 40 yards where normal velocity stuff will leave a lot of cripples.
Steel shot laws nearly killed duck and goose hunting. Then Mossberg brought out the 835 and goose hunters got a boost in performance. It was at this time that the 10 gauge made a resurgence from the grave. It had been nearly dead, but Ithaca brought out the mag 10 semi auto that Remington eventually bought the rights to. Browning has the BPS 10 and H&R, before it died, made the 10 on a bigger frame. The H&R was the least costly of the 3. BPS 10s can be had for somewhere around 700 to 800 dollars, my H&R cost me 200. I don't hunt geese often enough to justify a BPS 10 and I really like this H&R. I hold a round in my off hand, fire, kick it open and slam a round in for another shot. It's a challenge.
I've not yet pulled off a double, but I HAVE taken down a previously shot cripple with a second round. I'll eventually get that double.
I would say don't be afraid of recoil. It won't do permanent damage and I've been banging up my shoulder for a long time and in a day or two the soreness is gone. BUT, I'd avoid 3.5" 12s in lightweight pumps like my 535. The 835 is a heavier gun, but it ain't the 9 pounds plus that most 10s weigh. 9 lbs does slow the swing, but that don't really matter on a group of snow geese setting their wings over a rag spread and I don't dove hunt with the gun. :laugh:
Every tool has its uses. My 20 gets far more use than my waterfowl 12s and 10 now days. I have to talk my buddy into coming down for waterfowl hunts because we use outfitters and they require at least 2, sometimes 3 in a party. I'm getting old and have moved away from the WMA where I used to duck hunt a lot. I just can't stomp around in that muddy marsh like I used to could carrying deeks, marsh chair, gun, ammo and birds coming out. That's some tough hunting. There are some easier spots to get to on Buffalo Lake and I have a canoe for getting across to the spots on the other side, but the best hunting is usually back in the back where the mud is and is all walk in. Ain't that always the way? :laugh: