I wanted to try a bench bag, so started looking to buy one, but they are a ridiculous price for what is essentially a heavy nylon bag, so being a tight bastard, I decided to try one of the Chinese ones on ebay and paid about £11 including postage! It came quite quickly and looked just like the expensive branded ones, I filled it with cat litter, which had I read was good to use, but which was a mistake because its so frigging heavy, I should have used rice, its actually well made for the price, is absolutely solid on the bench and works much better than a bipod with my 30-06. I haven't quite filled it up enough, I ran out of cat litter, so it need 'plumping up' now and then, if it is fully filled it keeps its shape much better.
Here is the ebay link: Unfilled Gun Rest Shooting Rest Bag Outdoor Hunting Shooting Gun Access 6954207222748 | eBay
Here is the ebay link: Unfilled Gun Rest Shooting Rest Bag Outdoor Hunting Shooting Gun Access 6954207222748 | eBay