I use these in a 12 gauge 870 with absolutely no problems. I have about 5 extra full turkey chokes and have used these loads in all of them with great success. They are my favorite turkey loads. They should work great in a 20 gauge too. Use any full or extra full turkey choke and you'll be golden. I've even used them in an old fox sterlingworth with no problems: Have taken turkey at over 45 yds with that shotgun with its mod and full barrels.