RE: 20ga. shotgun, bird barrel, slugs or buckshot?
Make sure you try different slugs in your gun, my mossberg shoots a winchester slug a foot to the left while a federal slug shoots dead on. Different brands of buckshot will shoot differently too. Mine has a much better pattern with federal premium buckshot than with winchester buckshot. You'll have better luck finding 00 buckshot than 000 buckshot, but if you find the 000, snach it up, it puts a hurtin' on anything it hits. Whatever you do, shoot it at the range first to see how it does. I have a westernfield shotgun that patterns a foot low and to the right with anything (slugs or buckshot).
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