Accuracy tool framework

I am creating a structure for my accuracy tool. I was making use of light weight aluminum accounts for developing the framework, yet I discovered that the leading as well as all-time low are not completely alongside each various other.

Sight accessory 2403.

Any kind of pointers pertaining to the layout of the framework? Should I make use of various other products to develop the framework or there are any type of means to develop an excellent cuboid with light weight aluminum accounts?