TargetTalk

Has anyone of you experience from glass-bedding an Anschütz 2013 action in an Anschütz factory alustock? Are there any benefits at all, or is it only waste of time and money? From my point of wiev, the action must be pretty good and tight as it is, since it uses four screws, or...?

The point of glass bedding is to try to eliminate the instability that using wood as an interface to the action introduces. The epoxy fully supports the action in the barrel channel making the whole assembly somewhat more predictable in performance over different conditions.
Aluminum stocks by their nature are more stable than an epoxied slab of wood, this means that glass bedding is superfulous to the assembly and adds nothing to stability or performance.
Instead, buy a good torque wrench and pay close attention to your torque settings, adjust every time you shoot. Lot test your match ammo with varied torque settings to see if groups open up.
mike

Bo:
Bedding a 2013 is a much discussed subject. The four bedding screws of the 2000 series action do not necessarily provide better bedding than the 2 bedding screws of the 1900 series action.

That said, I've seen a couple shooters shoot very good prone scores with a unaltered 2012/2013. I asked the 2013 shooter how he torqued his bedding screws. He said "I did it just like it says in the manual. It makes a difference". I believe that is front to back. He used the funky torque wrench supplied with the rifle.

Most shooters who work on their factory stocks or have custom stocks made for the 2000 series action pillar bed their stocks. As I understand it, this is a job for a gunsmith who has done it before.
Alan Carey

If you look at pressure lines, glass bedding of a cylinder style action (1813/1913) makes contact on just two wavy lines along the bottom of the receiver. Once the bedding hardens, you don't get full contact. Many of the top European shooters don't bed at all. That's for a wood stock. Aluminum stocks (Anschutz, at least) use a high durometer polymer compound between the stock and receiver. It conforms to the steel, and has a larger contact area than glass bedding. With the square shape of the 2013, I'm not sure what the glass contact area would look like. Aluminum doesn't change shape with humidity, so should have a more stable surface to start with.

I agree that a torque wrench is the place to start. Always tighten the screws in the same order, and in several steps. It shouldn't be lot sensitive, unless you have a big change in velocity (I know, folks will jump all over this and say you have to adjust torque for each lot, but it hasn't been my experience). Your gun will have a torque that it 'likes', and that's what I'd stay with.

The barrel and ammunition combo will have a far greater effect, that takes a lot longer to fix and can cost a bunch more.