The deal with group buys is that a member of the group can buy the stuff from somewhere. For example, Lee sells bullet molds to people, so a guy can design a bullet and order 100 molds from Lee.
Remington/H&R sells firearms to distributors, not to people. If somebody who owned an H&R distributorship wanted to organize a group buy, it'd be relatively easy. Or if a group like Whitetails Unlimited or Pheasants Forever wants to order 500 custom guns to give out at raffles around the country, it's easy for them to find a distributor to partner up with them.
Bank in the Gardner days, it seemed like any distributor who wanted 100 of something could get it. Not sure about the current factory.