The reason most rifle builders use Marine Tex over Devcon is the Marine Tex Grey is a lot harder supporting 13,000 psi in compressive strength. Devcon will only support 8620 psi. This is one of the most important qualities for a bedding compond. In most other qualities like chemical resistance the Devcon is equal. Devcon requires 7 days to cure at 75 degrees where Marine Tex cures in 24 hours at 72 degrees. For the professional gunsmith the cure time can be a real issue when working with deadlines.
In the past I have had troubles with brittleness or shrinkage but since I started mixing it by weight those issues are history. I attibute the problems I was having to inconsistant mixing ratios trying to eyeball 5-1. The correct ratio by weight is 6.3-1.
Build a man a fire and you heat him for a day.
Set him on fire and you heat him for life.
Only accurate rifles are interesting.
Gordy and Brady.