Re: Bedding for aluminum stocks?
I thought the whole purpose of a chassis system was so that one doesn't have to go through the whole bedding ritual.
Me personally, if I bought one and my action didn't drop right in and shoot like a house on fire, I'd be looking for a refund on my purchase.
Things to consider. Some of this might be considered a bit "out there", so bear with me.
If a stock is made from carbon fiber and has an aluminum chassis embedded in it guess what you have? You have two materials at the extreme opposites of each other on the galvanic table. Now introduce a bit of electrolyte solution like salt water, a pinch of acid, or something else that will create an electric charge.
Guess what you now have? You have a battery and your receiver becomes a prime target for corrosion. Far fetched? Maybe but its something plumbers have to take pretty seriously.
If I shoot my rifle in a desert plane in AZ I doubt I'll worry much about it. If I shoot in a coastal region it should probably be taken more seriously.
Next, bedding to aluminum. AL is funny stuff. The reason why its used heavily in maritime environments is that when machined the oxygen in the air reacts with the surface almost instantly. AL oxide is formed as a result. This essentially creates a "hard candy shell" that prevents further reaction with the atmosphere. It also creates a boundary layer that prevents 99.9% of resins from bonding the way they are intended. the A380 airbus found this out when the composite wings began delaminating from the AL spar on the wings. There's a very "techinical" term for this phenomenon, but I'm afraid I forget what it is.
Now back to reality: A wing in a hundred million dollar plane at 40K feet is one thing. Our silly bolt guns is another. You can likely bed a chassis stock and it'll work just fine. However the other things to consider is that a paper thin layer of resin is very susceptible to flaking over the course of the rifles life. If your willing to deal with that as it happens then fine. I personally like to try and get it right the first time so I can move on with my life.
Try an experiment once. Grab a piece of AL plate, clean the snot out of it, and apply a thin layer of resin. let it cure and begin tapping on it with a broad faced object. It won't be too long before it starts to separate and you end up with little corn flake looking chips falling off the stuff.
If I were to build a chassis system I'd personally surface model the receiver and machine it with a ball endmill programmed to step over .015" for each pass. When completed you'd see a surface that accurately emulated the contour of the receiver. It CAN be done. (just look at a turbine blade, impeller on a turbocharger, rotors on a supercharger, etc)
The issue becomes cost because even if you have a modern CNC mill running 15K rpm and 300ipm feed rates your cycle times are going to be quite long and this elevates the cost to the consumer significantly.
Its for this reason you see the large stepover at the tool path for most chassis setups. If mirror image surface contact is the goal (which it should be in my mind as bedding is supposed to produce a precision casting that is tension free) your only fooling yourself.
Just my two bits. Take with salt.
Hope this helps.
C.
