Depending on condition, $150-$200.
640k 22 mag was manufactured from 1959-1984.
There are limited references on the 640K. Mine show the 640K made 1959-1960, the 640K-A from 1960-68, and the 640K-D from 1969-1985. My best guess would be after 1968. Vic Havlin at havlinsales.com runs the Mossberg Collector's Association, and may be able to narrow down the dates.
Pre 1968
the western field model 822 was made by mossberg,and the matching model number from mossberg would be a model 640K.
Revelation Model 107 was made by Mossberg (Model 640K)
mossberg model 640k takes m339 5 round clips about $30 each
the rifle was made by western auto its value im sorry i dont knowAnswerSold by Western Auto, but probably made by Mossberg or Savage. AnswerThe rifle was mfg'ed for Western Auto Co. by Mossberg and is a variation of the model 640K / 640K-S whick is a variation of the 620K ... Mfg'ed 1959 / 1984 ...Value, depending on condition to $150/$175 ... I agree that this is a Mossberg and in my area sells for $175.00 and up in excellent condition. I own one and it is a keeper. I haven't shot any current .22 mags that are any better quality!
Made by Mossberg, and labeled with the Western Auto Revelation brand, your rifle is a Model 640K. If it has no serial number, it was made between 1959 and 1967. Rifles made in 1968 and later were required to have serial numbers. The model went out of production in 1985.
SEMI
If your rifle is a Model K (not a 151K, or 640K, just Model K) THAT is going to be a challenge. That rifle was made from 1922 to 1931. I would suggest that you contact Vic Or Cheryl Havlin through their website at havlinsales, and that you check the Mossberg board at the rimfirecentral website. The Havlins perform gunsmithing and sale of parts forr Mossbergs, and operate the Mossberg Collectors Association. Good luck. Did that thanks, I actually belong to the Mossberg Collectors Association. They do not have parts right now. This is actually the "s" version of the 22 and is missing the loading assembly I am hoping to find a parts gun so that I can restore this one I think the parts from the "k" model will work also.
IF your Revelation rifle is a bolt action .22 Magnum, with a box magazine, it was made for Western Auto by Mossberg as their 640K model. These were made from about 1959-1985. Some of the cross reference data is a little fuzzy.....
steve job