According to Ned Fall's book, the Victor Plain American Gun Co. was made by Crescent and sold by H & D Folsome. Probably made in late 1800s or early 1900s. Value runs from $10 to $200 depending on condition. Google is your friend and there is info on the internet about the gun, gun manufacturer and the distributor.

 

H&D Folsom Arms Co. built these Victor single barrel guns at their factory in Norwich, Conn. During different time periods they use the American Gun Co. or Crescent Fire Arms Co. name for the guns that they marketted and also stamped them with myriad "trade names" that other dealers/wholesalers/jobbers requested. According to the serial number list the late Joe Vorisek compiled, Volume Nine, Issue 4, Shotgun Research Newsletter, your gun is from about 1913. From H&D Folsom's Catalogue No. 18 which is just after WW-I --

Here is the parts list for the single barrels from a 1915 American Gun Co. catalogue --

 

I inherited my grandfather's old shotgun that sat in the corner of his closet for as long as I can remember----I never thought much about it till now. It's in poor condition wood cracked and duct taped together, but I was wondering about the age of the gun. It's A Victor Plain 12 ga., single barrel shotgun with a center trigger. It looks like the one with picture on your page here made prior to 1915, but was wondering if the serial number could help me better pinpoint the age. It is #278384. You guys seem to be the best resource about this type of information.

 

All the records from Crescent Fire Arms Company were lost or destroyed in a scrap paper drive during World War Two. The late Joseph T. Vorisek re-established the serial number-year made tables during his research for his book "The Breech Loading Shotgun In America 1865 to 1940. I'm sure he took the total number of guns made and divided that by the number of years a particular gun was made and worked out the average number of guns made each year. It ain't the best in the world but it's all we have. According to that listing, your gun was made in March 1910. Serial number range for 1910, 273,001 to 294,000: for a total of 21,000 guns made, Divide that by 12 comes out to 1,750 guns a month. Add up monthly production and in March it comes to 280,000. Now I'll bet you will want a value. These guns were inexpensive (by our present day standards) selling for $10 to $15 new. That was back when wages were maybe $1.00 to $2.00 a day. They haven't appreciated much over the passing years. A prime condition example (rare to very rare as these guns were used hard and received little care or maintenance) that appears to have come out of the factory yesterday afternoon might sell at auction for maybe $100 while a rusty and pitted metal, rotten or broken wood and missing parts piece of junk fir only for parts salvage or as a whisky still stirring stick might fetch as little as $10. Of course sentimental value can't be calculatedt