I often use McMillan fiberglass stocks in my projects. In addition to building rifle stocks, McMillan also builds complete rifles (at least used to, they sold that part of the business) and does custom gun work.
McMillan posted these videos on YouTube in 2013. You can gain some insight into the manufacturing process (my apologies to Rifleshooter.com’s subscribers, the email you’ll get won’t have the videos attached, you’ll have to log onto the website).
Watching these short videos you can pick up some techniques that can carry over into your own work as well as gain an understanding of how fiberglass stocks are made. For instance, note how they chamber barrels between centers and how the actions are prepped prior to bedding a rifle.
Building a McMillan Custom Fiberglass Stock
Inletting a Stock
Receiver Truing Process
McMillan’s Barrel Chambering Process
Assembling a Mcmillan Rifle
Bedding an Action McMillan Style
McMillan’s Finishing Stage