Well, someone is more likley to come back with 50% in a gun, instead of 10% like a lot of gun shops require for layaway. Besides, have you ordered a gun from a dealer lately? More than likely they'll want a good % to special order something, especially a weird caliber or model.
As for returns, you can't give a refund on a used firearm, Wal-Mart doesn't sell them.
All this is company policy stuff.
I understand the manager-walking-you-to-the-door thing, too. When they sold handguns years ago, they had an employee killed by some nut who bought one and some ammo to rob the store...
Don't forget that walmart is a huge corporation, and everyone has to anwer to someone else.
I just bought a 45-70 from them a couple weeks ago. Wasn't too bad of a process. I really didn't like the layaway thing, though. I really think they should handle that in sporting goods, but oh well. It is what it is. If their prices weren't so good on the less expensive guns, I'd try to deal with the local guys, but the Handi's are just to well priced to blow the cash elsewhere.