Never had a problem with Nitro shells and I have shot their loads in both hevi and tss, in 20 and 10 gauge. I do believe they are over pressure and a friend that reloads sent one off confirming that. At one time, they were the only game in town when it came to high performance shot shells you could purchase. Now, there are many other players in the game and more arriving daily. I wouldn't hesitate to shoot Nitro, but it is easier for me to get similar performance out of others now.