Your Sears mod 66 is really a Hi Standard C1200 or C1211. The disassembly instructions can be found here:
http://www.histandard.info/manuals/hsashotguns/0368D150R.pdf
Yes, you can remove the barrel of a model 66 Shotgun!
High standard
The Sears mod. 66 was made by High Standard for Sears and is a High Standard mod. 66. If you have anymore questions please do not hesitate to email me at eagle44mag@adelphia.net. Thanks, Rick
50-200 usd
The following link will give a general ides but I wouild need the assembly date code from the barrel to provide the month and year. http://www.histandard.info/PDF/Sears%20Shotguns.pdf
The value of a Sears Roebuck M-66 gauge automatic shotgun depends on its condition. This gun in excellent condition is valued between 120.00 and 180.00 as of 2014.
The J.C. Higgins Model 66 shotgun was produced by the High Standard Manufacturing Company. It was sold under the J.C. Higgins brand, which was a private label used by the Sears, Roebuck and Co. department store. The Model 66 was a popular pump-action shotgun, particularly in the mid-20th century.
An automatic shotgun from Sears Roebuck would top out at around $200.
i also have one of these sitting in front of me. they are worth around 150-200 dollars. mine is from the circa-1947 era. The Model 60 first appeared in the Sears Catalogs in the Fall/Winter 1955 catalog and the Modle 66 which superceded the model 60 first appeared in the Fall /Winter 1958 catalog. The Model 66 should have an assembly date code on the barrel.
i have this gun in my home so if you send me a e-mail on helgeh78@hotmail.com i can post you some pic of it back to you:-)
your shotgun was made by high standard just prior to 1980. value will depend on condition mostly. i can estimate that one in good condition will cost around $200.00 to 300.00. High Stadnard stopped making the model 66 for sears when the Ted Williams 30 made by Winchester was introduced inteh early 1960's High Standard was completely out of the shotgun busines by early 1977. THis link is to a chart that shows the dates when these shotguns were cataloged by Sears. http://www.histandard.info/PDF/Sears%20Shotguns.pdf
12 Gauge 20" double barrel shotgun made in TULA USSR very nice gun, some worth more than $2500 usd