*Update...Ithaca Gun Company (Ohio) also approved the use of tungsten alloys such as Federal Heavyweight, Hevi•Shot, Hevi-13.
born2hunt...I would just run that through Les Hovencamp of Diamond Gunsmithing or Ithaca Gun Company first as you have a full choke...especially if it's an older model like mine. You might be fine, but I certainly wouldn't want you to risk damage to you or your Ithaca. Especially since there is a good lead option for lead and a full choke with the Winchester Rooster XR (similar to the Long Beard XR in respects to the resin buffer and tighter patterns...but, is available in 2 3/4"). But, I understand the desire to run the Hevi-Shot #7s with the pattern density. Send them an email, they responded rather quickly. Good luck!
Steve