I'm not familiar with the Regal designation, but I just bought a 13 year old Mossberg 500C, 20 guage pump, with vent rib and accu-choke(modified tube installed), for $150. It looks like it was never fired.
100-300 USD depending on condition.
Your revelation R310C western auto shotgun is a Mossberg model 500C which was made by Mossberg and Sons for Western Auto.
http://www.e-gunparts.com/productschem.asp?chrMasterModel=0840z500
if it is a rare gun ,300-900 uds
You can get your parts from mossberg . The mossberg model 500C is the same gun. You will need to call to order the parts.You also may find the parts you need at www.e-gunparts.com. Thay Cary most of the parts for this shotgun.Some parts you can only get from mossberg
Your question can't be answered as written. What Model? What are ALL the markings? What gauge? How long is the barrel? What type of finish? Mossberg 500C, 20 gauge, 26" accu-choke, serial number K064007, checkered wood stock, blued barrel, vented rib barrel.
You can get parts and information at the following web site: e-Gunparts.com/Forums/MessageBoards. The Revelation 310C is the same as the Mossberg 500C.
2627mm = 2000d = 500c = 100xx= 20v= 5ii= 2mmdcxxvii:= 2000 + 500 + 100 + 20 + 5 + 2= 2627
500ºC = 932.0ºF
There is no difference. A 500 is a basic Mossy 500 receiver shotgun. Unless the gauge is stated, it's assumed it's a 12. The 500A is simply stating it as a "12 gauge" 500 in its name. The Mossy 500A is a 12 gauge model 500, the 500B is a 16 gauge model 500, the 500C is a 20 gauge etc. There was no 28 gauge so there is no 500D, contrary to many sources, so the next one was the .410 called the 500E. A 12 gauge model 500 and a 500A are the same gun.
The model 500 Mossberg is a particular style introduced in 1961 by O.F.Mossberg & Sons. It has undergone many style changes over the years, but 500A, B, C, or D are not style changes. A model 500A is the 12 gauge version of the model 500. 500B is 16 gauge. 500C is 20 gauge and 500D is .410 (which is actually a caliber rather than a gauge.