Chet ...
STOCK TAPE is the secret. Add Pure Silicone Spray to a cordura bag surface and things really start moving.
I have found this company to be a great source for stock tape:
http://cshyde.thomasnet.com/category/tapes-with-psa?. They will cut rolls to the size and length you want. I use #19-5A, cut to 5 inches wide by "5 yards" long. Cost was around $26.00. #19-5A has an acrylic adhesive which holds up better in heat versus a rubber adhesive. I make sure I clean my stock area with soap and water to get all the dirt and oil off it before I apply the tape. I have a good finish on my stocks so the soap and water has no effect on the surface.
The tape that I buy...mentioned above...is $26.00 for a roll 5 inches X 5 yards or 5" X 180" or 36 pieces of 5" X 5" which equates to 72 cents each. [180" divided by 5" = 36. $26.00 divided by 36 = .72]. 2 ea for 5" X 5" for $6.00 is $3.00 each. 4 for $10.00 is $2.50 each. Why over spend ??? 72 cents a sheet is inexpensive. 36 pieces too many ??? Order a shorter roll.
CS Hyde was also very helpful when I was researching tape and sent me four samples. I dealt with Sheridan O'Brien who I believe is one of the company's principals. As I recall the conversation she also does some shooting and understood the application. Give them a call.
I use KEL pure silicone spray on the ears of my cordura and leather rear bags, and front bags.
I go directly to the source: Kellogg's Professional Products, Inc., Sandusky, Ohio, 45870. Ask for Stock No. 57500 (110A).
I pay $7.05 each for the tall "10" ounce cans. You can call them at 1-800-334-2130.
Hope this helps.
Art