The problem isn't the saw (either a miter box or a compound power saw), the challenge is the set up. You'll have to set the saw on a table and then use at least two or three, but four is better, sawhorses to support the length of the mast and be level with the cutting surface. I have foldable sawhorses that have adjustable feet, I set them at the highest so the are above the level of my work surface because when the saw is set up the mast section is about 2 to 3 inches off the surface of the table. A couple packs of plastic shims helps level up all the sawhorses and even the saw or miter box. Just make sure the mast is fully seated and squared up, clamp it down. Nothing should move while you cut.