Shin-Tao,
I have an H&R single 12g TOPPER Model M48, Choked, bead front sight. I've used it for skeet, ducks, deer, rabbit and other small targets of opportunity. Ammo includes #9, 8, 7-1/2, low and high brass 6 and 4 and 00 buck.
In 1948, at age 15 in New Jersey, taking some earnings from pin setting for bowlers, I rode two buses to the sporting goods store, looked (longingly) at a double and settled for this H&R, a box of shells and a hunting license. With the box under my arm and the bag in hand I rode two buses home. Try that today!
I have been happy with this shotgun, had good times, took some game. It is here today, 52 years later, still shooting. I will pass it on one day to a son or grandson who should get, no doubt, another lifetime of value and good times. In all this time, only the firing pin has been replaced.
I paid $16.00US (hard-earned at $.05 a line in bowling).
Enjoy, even if it kicks... it's a great shotgun.
-Andy