Actually, I have 4. One which is .45 ACP/12 ga, one which is .32-20/20 ga, one is .22 LR/12 ga, and one which is .22 LR/20 ga. The .32-20 is a cheap aluminum one which is so poorly made I'd never put a shell in it for fear I couldn't get expanded case out again. The .22/20 was bent so I only tried it once. The .22/12 was made by Shell Shrinker (now out of business) and works well. The .45/12 has an 18" barrel. Once I got a Partner 12 ga barrel for my Handi Rifle (with sights), I got three shots touching at 25 yards and a 3" group at 100 yds. I got that from MCA Sports in Alaska. Only modification I had done was to bevel the rear of the insert so I could remove the spent shell with my finger nail. Fact is I got the Partner barrel just so I could use the .45 ACP insert and am happy I did. Next time at the range I'll try the .22/12 in the barrel with sights to see how it groups. I think the inserts are a great idea and look forward to trying some others.