Do any of the non Devcon products list their shrinkage and other specs?
Most will say Non shrinkage, But in truth they will all shrink a little. The amount depends on how hot it gets during curing. Heat is caused by Exothermic reaction and if it is still there after it becomes solid, When it totally hardens the compound shrinks like any other material that cools.
I have bedded hundreds of rifles/actions and the end results will tell you how much it shrinkage you have. Most will feel good and last for a long time. Some will be difficult to remove from the stock even though they are not mechanically bound. This is what you want.
If you can remove the bedding/action screws and the action will have to be worked out squarely, it is a good bedding job. The tighter the fit, the less shrinkage you have. Bedding that has been done right with the best compound will last the life of the rifle unless it is taken out every time it is cleaned, and even then it will last for many years without becoming loose.
The better the fit the more consistent the accuracy.
Many products that people use are not designed for bedding and heat and shrinkage are not an issue or requirement for it's intended use. Strength, bonding and setting time are. So what seems great at the time, may/will not be the best for this application.
The reason for bedding in the first place, is to get the best fit between the stock and action. Any shrinkage will detract from this. So Use compounds that are designed for bedding and you cant go wrong.
Just My experience based on many years of bedding with all available compounds and seeing the end results over time and use.
J E CUSTOM