Wire size question

My plans potentially changed this weekend when I came across a 20' piece of aluminum 4wire 4 gauge left over from a previous installation (ground appears to be a 6Gauge). I was going to run a 30 amp service to my brew room and use a 50amp GFCI spa panel for protection.

Now that I found the 4 gauge wire I have the wire capacity for the 50amp circuit (yes I have the panel capacity). but my question is. Will a standard 50amp circuit breaker have large enough connections for the 4 gauge wire? Also will the 50amp GFCI Home depot panel have adequate sized connectors?

I have a seimens panel that uses QP style breakers but I'm quite sure that won't make a difference.

I consider myself fairly handy and wire up plenty of stuff in the home. But only copper wire. Personally connecting Al wires between panels is something I would leave to an electrical contractor.

If you go for it, you will need to make the connections with set screw connectors rated AL/CU and antioxidation paste. There is a technique to tightening the connections because they tend to relax after a while.

https://www.homebrewtalk.com/f170/running-wire-conduit-391667/index3.html

Understood and accepted. I've worked with aluminum in the past, and agree with all the points you've posted. I'm mostly concerned with spending $100 on breakers and the connectors being too small for the wire size. I've tried to find spec's on max wire size without much success. I guess what I'll do is take a 6" piece of the wire to home depot and check in person. I have no desire to cram a wire into a crimp that it was not designed for.

The breakers I have can accept up to 6 gauge stranded, or at least the 25amp one does.

FWIW, Square D QO breakers 35 - 70A accept 8ga to 2ga wire. Should be able to find the spec. for yours online somewhere.