no problem. we've had a 20 gauge single shot pardner in the family for almost 20 years & it still works great. i'd recommend a recoil pad since these guns are fairly light & can kick like a mule with heavy loads.
H&R's barrel program also let's you put a different gauge barrel on the same receiver, so if you bought a 12 guage & want to shoot 20 gauge or get a rifled slug barrel, send it to them & they will fit another another one.
NEF Pardner single shot shotguns are fine examples of a good budget single shot. My great grandfather had a H&R that was made probably over 100 years ago. It has a home made firing pin in it. But it still will fire. Though no one shoots it any more. Same basic design. There is not a lot to them. They kick pretty good because of the light weight and lack of a butt pad. But they work.
I have 3 break opens, 1 O/U, 1SxS and 1 single shot. The single shot is a new england arms pardner in 410, it was my first gun and I still love it to this day, shoot rabbits with it every season. I would highly recommend them to anyone!