Banks offered a number of guns this way including Weatherby's, Colt Pythons, Colt Python-Diamondback sets, Colt Sauer rifles, and others. I sold off one of the wood cases for a Python/Diamondback set a while back from a bank in Finlay Ohio. Anyway, they are referred to as bank guns. It happened in the mid to late 1970's to early 1980's when interest rates were above 12% for bank CDs. A lot of these banks failed during the "Savings & Loan" crisis. Inflation was also quite high then too. You gave them your money and the gun came as a prepayment on future interest. It was a great idea, but interest rates are too low now to make it a practical option in terms of time.
One of my favorites back then was a savings & loan guaranteed a value of $1,000,000 on a bank account if you deposited $1,000 per month into an account with them. I don't recall the number of years for the investiment, but it was in the order of 20 years.