Just picked up SKB model 500. Does anyone know where to obtain an owners manual?
In the interim, there appears to be a selector switch just above the trigger. Can someone tell me which barrel fires for which position? Also which barrel, top or bottom is the more open choked?

Lastly, this is my first O/U and I was wondering about the proper lube and where to lube the action. Thanks

http://www.skbshotguns.com/initalpage.htm SKB shotgun were made back in the 60's and later. You would need to know your model number 500 guns age. The bottom barrel is more open/fixed chokes. I lube the hinge pin with Rem oil.SKB had many different importer over the years. You can look at the website or email SKB

The barrel selector on an O/U is typically marked so that when in one position it will expose and "O", which means the upper (over) barrel will fire first. In the other position a "U" will be exposed which means the under barrel will fire first. Remember, it is the exposed letter that is the key, not the letter toward which you push the selector. But the real way to find out is to shoot it, erasing all doubts.

Conventionally, the lower barrel is the more open choked.

The action needs very little lubrication. A very light coat of any gun oil is adequate.

SKB's are well-regarded. The action feels a bit loose compared to a Browning or similar type action, but that is inherent in its design rather than being a result of wear.