RE: NEF Pardner 10ga.
It will be fine. No point in buying expensive slugs either for a smooth bore. Just get yourself a box or two eachof Federal, Remington, and Winchester plain jane cheap foster type slugs and see what shoots best.
I gotta believe though that shooting that thing with slugs from thebench is gonna kick your butt into the next county. I suggest a slip on recoil pad at the least