[QUOTEI try to avoid glass bedding. Machined aluminum block is IMO a far superior and more long term durable solution. Glass bedding degrades and weakens with shooting. When I do "glass bed" a rifle, I do it with original formula J.B. Weld and use Turtle wax hardshell wax for the release agent. ]
Epoxies are ,or can be,engineered for a particular purpose. I'm not commenting on JB Weld. Maybe its accidentally great for bedding.
If,in my experience,my chosen bedding compound was failing me,I might question my choice.
I'm sure Brownells consulted /collaborated with the epoxy manufacturer to select an epoxy appropriate to the task.
Dexcon s a specialist in filled epoxies. I'm not too bashful to call a tech dept and ask questions.
One characteristic to be aware of is the "stacking" of the filler to become interference.
Aluminum bedding blocks can work,but beware.
There is a reason Nesika Bay wire EDM's their receivers out of pre-hard steel.
All receivers warp in heat treat. They are not re-machined.
The CNC machined bedding block will not perfectly fit a warped receiver.
The pillar and Vee block technique for a round receiver begind with surface grinding two flats on the receiver to mate to the vee-block.
I used a Hermann Schmidt vise and precision angle plate to regrind a Husky receiver floor, lug,rails,and receiver face flat and square. That gave the Lilja barrel a chance to shoot. It does pretty well.
In order for an aluminum bedding block to fit,you need to know how to use Dykem Hi-Spot and a scraper. With absolutely minimum torque on the screws,if you get 90 % blue transfer from the receiver to the bedding block,you have something.
I'm not bad mouthing bedding blocks.
I'm cautioning against unverified assumptions about fits.
You cannot assume a heat treated steel receiver remains straight,square,flat and true.
If your guard screws turn 1/4 or 1/3 turn coming up to torque,what does that tell you? Food for thought.[/QUOTE]
But, its guaranteed a glass bedding job will break down with use.