There are two separate Bud's services in play here. If you place a standard item on layaway AND make the 20% down payment immediately then the item is pulled and the price reserved at the layaway price. It will not "sell out" on your order. If you don't make the 20% immediately then the item can sale out as you really haven't made the purchase yet until the 20% deposit is paid. To be clear Bud's policy states: Upon receipt of your non refundable 20% deposit (personal check, bank check, money order or credit card), we will secure your firearms(s) from our inventory..." The other situation is on a "reserve" gun. You can order (reserve) an out of stock item (if eligible) and make payments on the gun while waiting for its return to stock.

I believe they don't secure the product until the initial 20% is received. Once they get that the secure the product for you. So as long as you made the minimum payment to secure the product you should be good.