i've used them in both the 12 ga and 20 ga with excellent results. They usually don't go very far with a good hit. A great testimonial about their performance is this year my dad shot a nice buck @ about 45 yards with his setup in 12 ga. The slug went through the heart and the deer went 40 yards. The amazing part is that he did not see a sapling of about 4 inches in diameter right in front of the deer and the slug passed directly through the sapling before connecting with the deer. The entrance hole was very small in diameter and another portion of the slug entered the leg, and still had devastating results.