Does it seem to shoot tighter or just harder than lead.
What length and shot size are you all using.

The Hevi-13 shell will shoot harder than lead for sure. Tighter all depends on the type of choke that you use. Just like any other load that you use for turkey hunting, you will have to do some expirementing to find the choke that works the best with the Hevi-13s for you specific gun. It does, with out a doubt, hit harder than lead. Winchester Supreme Elite Xtended Range, Federal heavyweight, Remington HD are a few other Hevi-shot based loads that may or may not perform better than the Hevi-13s. I prefer the 6 shot loads, especially in 'heavier than lead' shells because you get more pellets in the shell...resulting in more pelletes on the target. Because of the more extreme density of the 'heavier than lead' shells, a 6 shot shell will have the same energy and impact as that of a 5 shot lead pellet.

Here is what the 3 1/2 ,2 1/4 #6will do at 43 yds out of a Super X-2 and a Rhino .670 shoke. The shot blew through 3/8 chip board at 43yds also.

What r33h said and: Because it is harder than lead, the pellets deform less during the trip down the barrel and through the choke. As a result, they fly straighter, and the pattern doesn't disperse as much.