Probably because the experts aren't left handed and neve tried to load an 870 with heavy winter gloves on.
Crossbolt safeties SUCK for a left handed shooter, just plain SUCK, no other word to describe it. HERE ME, SHOTGUN MAKERS, CROSSBOLT SAFETIES SUCK!!!!!!!!!!!!!!!!!!!!!
Did I tell ya what I think of crossbolt safeties?
Besides, is there a double barrel out there, either OU or SxS that has a crossbolt safety? Nope, they'fre built for speed. No fumbling with a crossbolt safety, right or left handed. Crossbolt safeties suck. It's cheaper to build a crossbolt safety, no doubt why Remington and others do it. Cheap, cheap, junk. They suck.
I sold my Wingmaster . I've had two Mossbergs. One was a 50s contract "Revelation 310" that was still shooting after I sold it, just wanted a new camo one. I could still be shooting that Revelation, know the guy that owns it, still a good shootin' gun, 50 years old.
Maybe the military wants something without a crossbolt safety. Maybe there are left handed soldiers out there and they need to shoulder the weapon with speed? Maybe the military knows that crossbolt safeties suck?
My 500 has a Winchester load stick in it once in a while. Miffs me off, have to take the barrel off and get it out with my leatherman. It's the ammo, though. I know a lady on another board that has reported the same problem with Winchester Xpert steel loads in her 870. I'm going to switch to Kent Fasteel. I've also, years ago, might have fixed that, had Remingtons hang on the ejection port of both Mossbefrgs I've owned. It was the fact that the loads were too long after firing. Did not have the problem with Federal or Winchester. Haven't used Remington 3" in years now, so it may be fixed. But, I'm still gonna try Kent or just go back to Federal.
BTW, crossbolt safties suck.