PickettSFHunter":1ga5teo6 said:
What makes the federal heavyweight 7's better than Hevi 7's in a 20?
Lead is a little less than 11 g/cc. It is soft, so it deforms some when fired due to force of set-back and constriction through choke. Not terribly deformed, but not really spherical any more. The deformed pellets have a relatively poor ballistic coefficient, so patterns fall appart more quickly. The "shot lock resin" in the longbeards is said to prevent this pellet deformation thus improving patterns.
"Hevi" shot is 12 g/cc, so just barely heavier than lead. (The old "hevi 13" was 13g/cc). You get slightly more downrange energy, but not much. But, the shot is a hard alloy, so it does not deform when shot. However, many of the pellets are basically deformed when the put it in the shell. Very poor consistency in pellet size and shape, and most of the pellets in the blended shells are 7s or smaller with a few bigger sizes sprinkled in. The good patterns mostly come from large numbers of smaller pellets. They will flat mash turkeys at reasonable ranges, but so will lead. I know they have a faithful following, but IMHO, the magblends are not as great as they are held out to be. But slightly better than most lead (maybe not better than longbeards, but that's a judgment call)
Fed. Heavyweights are 15g/cc and are very uniform, pollished pellets. Because they are nearly 40% heavier than lead, 7s retain plenty of energy at 40yds +. Plus they have an excelent ballistic coefficient and more kinetic energy per square inch (i.e. Penetration) because they have less surface area but equal mass as larger lead or hevi pellets. And there are about 220 HW 7s per oz. More per oz than lead 6s.
TSS is 18g/cc and also perfect pollished spheres. It is nearly 65% heavier than lead, so you can shoot 8s and 9s (260-350 per oz)to 50+ yards, no problem. But it is not available in a commercial shell, so HW 7s are the best thing going for a factory 20 gauge load.