I know longbeards have been discussed on here 1000 times but I never could find a good answer for this. How does the knockdown power of longbeard 3.5" #6 compare to the HTL loads like 3.5" hevi 7's or Nitro 4x5x7?
I don't think it will be in the same ball park as the HTL. Now it patterns as good or better in some cases. I did see this past few weeks a guy came in and had his own target holder. It was plywood and never shot. He shot a few different loads of lead. They was at the edge of plywood and the Long Beard was in deep that you had to look in the hole to see. It shock me that it did do better then other loads.
Knockdown power is a bit of a misnomer. What kills turkeys is pattern density coupled with penetrating ability of the individual pellets. First let me say that all the loads you mention have more than ample pattern density and pellet energy/penetration at 40 yds. But more specifically, lead 6s and true sized HS 7s have almost identical penetration at all reasonable turkey killing distances. Hevi 13 7s have a mix of shot sizes, some larger than size 7, some smaller. They will likely put more pellets on target than will the LB 6s. Some of those pellets will have more penetrating ability than will lead 6s, some less. The same can be said of the Nitro 4x5x7s. All the pellets larger than size 7 have more penetrating ability than lead 6s. All pellets smaller than size 7 (and there will be alot of those in that load) will have less. So its basically going to come down to pattern density and how many HS pellets size 7 are larger are contained in the two HTL loads you mention.
What ^ said. If you want to pay for lead, shoot the Longbeard 5's for definite knockdown past 40 but if you misjudge a little the LB 6's should definitely do it. If when you misjudge you do so by say 10-15 yards then I would go with the 5's. The 4's can be nasty as well out further if you misjudge that much, but that is quite a bit. That's if you want to stay in the lead price range. Hevi 6's will keep pace with those 5's usually and possibly a bit further. Never used the 7's so I can't comment on killing power. The 4x5x7's I have never used but if the pattern as good as the rest and, again, you want to spend the money then no issues there for the same distances. I have killed with hevi 6's well past what we are allowed to talk about and have seen the LB 5's and 4's do the same. But if you are great at judging distance and also strict to the 40 yard rule, as SumToy says, how dead is dead? Many a load out there can handle that job for a lot less (HV/Supreme XX #5's and 6's, Super X #5's and 6's, etc). I run an old Remington Hevi #6 in the barrel backed up with LB 4's just cause I like seeing those big ol holes in the paper, knowing good and well the 5's land a few more on paper. That and I have been known to misjudge the open woods/field distance.