Catdaddy,
Always use a choke in the gun. It will help patterning and protect the threads for the choke. Fabs is right on with the 10 and 12 ga thing. I have shot quite a few shells from both gauges. Without a doubt the 10 ga will kill farther than a 12 any day..in the hands of a good shooter. Poor shooting is just that..poor shooting. Finding the right shot size that patterns at the longer ranges is what makes the difference. When I was guiding every day..I could consistently kill canada geese at 70 yds. You must understand...I shot a lot...especially pass shooting. I really enjoyed pass shooting but the thing I really liked was fooling those ol geese and getting them right in the hunters faces. My average shot when I was guiding was more than 40 yds. Of course I didn't shoot till the paying hunters were done. I liked getting geese in to at least 20 yds and preferred 10 yds. Gave the hunters a really good chance to get their goose. So I did shoot a lot of big shot and big guns and found the 10 outclassed the 12 by a good 15 yds. Maybe more in the right hands