I'm pouring over a ton of information right now. Thanks to the world wide interwebz I've found early Hevishot info going back to 2007 I believe. There was, as there is now, quite a bit of confusion and misinformation, especially from manufacturers afraid to have the stuff run through their choke tubes for fear of damage. The stuff I'm finding was before the T load had been introduced and was little more than a whispering. Federal FliteControl was at that time being developed for law enforcement application. TruBall was on the horizon as well.
From what I've found, there has long existed a fine line between proper constriction for this load and too much constriction and blowing the pattern. To further complicate the experience, this line has been a moving target from gun to gun even within the same model. Amidst the info are tales of killing dogs at 68 yards or better and even reports of 100 yard shots and 100 yard patterns where pellets still tear all the way through 3/8" plywood. I'm not sure I can buy all of what's being sold in these cases, there is a serious dearth of photos for reference or comparison.
I had hypothesized Carlson's tubes were not constricted enough for the 835. I still feel this may be the case with the Longbeard. The Truglo is the bar to beat for turkey shot despite seeing a more than 100% percent improvement in pattern density through the Longbeard choke simply by switching loads. It still falls short of the Truglo by about 30 pellets. At 105 pellets in 10" it has only just matched what the Truglo had done with lesser ammo.
On to the Hevishot which I believe is a "tungsten matrix". In this case, I feel the Carlson's Dead Coyote choke is about right on at an exit diameter of .690 or a constriction of about 8 tenths of an inch. (it may be .084 or .085 depending on the source) I fired 3 rounds of the Hevishot Dead Coyote 3" 1-1/2 oz T 1300 fps, all at 40 yards. My first shot I pulled left, the second shot I was more careful and centered the shot over the target. The third shot I tried through the Longbeard choke which is 7 thousandths (.007) of an inch tighter in constriction. While the pattern was generally smaller in size, it was beginning to do some crazy stuff like form branches. (this was also the case with the Winchester Hi-Density Coyote B load) In comparison, the pattern with the Coyote tube was fairly symmetrical. (On a related note; Trulock has recently updated their site to include a mobile site. They too recommend a tube with an exit diameter of .690 for the 835 and predator loads with specific mention of both the loads I've highlighted here)
I found all 50 pellets on my target with a general over all diameter of about 34 to 36" at the widest point. 38 of the 50 pellets are within a 30" diameter for a 76% pattern. A 10" circle in the most dense part of the pattern (a little low and right of center) yields about 10 pellets.
The pics aren't great and I apologize.
I'm not sure what it would take, but I'd like to see tighter than this if I were going to be comfortable with a longer shot at an animal. I'd really have to shoot this combination more to see how consistent this is. The logo on the box says "I didn't come this far to miss". This may be a legitimate 50 yard load and my patterns are still better than those had by the guy in the YouTube video I posted back a little ways. That guy spent $15 on three rounds to get 2 pellets on target at 70 yards and still claimed that could be a kill. Well sure, it could be. With practice I can make this pattern effective but for the price I still like the Winchester Coyote B. I've already had occasion to use it on the property but not on dogs. In each case, the critter stopped where it stood. One rolled back a couple feet. These were smaller than coyotes though. For general use, I'll keep the Winchester loads handy.
In closing, for this segment, I like the coyote tube from Carlson's. It patterns well with the pairing of recommended loads though I'd still prefer a more dense pattern with the expensive load that is the Hevishot. The couple times I've needed it, I was confident in the pattern density of the Winchester for smaller than coyote sized varmints. For larger, perhaps the Hevishot would be the way to go.