When patterning that gun, don't forget to also use the factory choke tube. I'm not sure which model you have, but the Longbeard SXP seems to shoot the Longbeard XR pretty well with the factory setup (article linked below). With that said - the Carlson choke that came stock with my Ithaca was the best choke I could find until I found an after-market Carlson Longbeard XR choke tube in Cabela's Bargain Cave...

https://www.americanhunter.org/artic...beard-shotgun/