A swarm of #6 shot at 1150 f.p.s. will certainly do the job at reasonable ranges. I like to recommend 40 yards as the longest shot at a turkey however.
It's all about the retained energy at the target (turkey head/neck vital area) and as long as we do our job with good shot placement, those loads will work just fine.
A little time spent at the range will let you know if you're getting that swarm of shot in the right area.
All my best this spring.
"If he's out of range, it just means that he has another day and so do you."