I have a steel NM free float tube I want to make lighter, by making skeletonizing cuts or drilling holes, or both. I have tons of "normal" free float ARs etc, but with this one, I want to retain the standard look and do something interesting.

My questions are:

- How much lightening is too much before structural integrity is compromised? Is there a good way to tell before starting?

- Is there a most efficient way to maximize material removed while minimizing loss of strength? (Horizontal cuts, repeated holes drilled etc)

- Am I correct in thinking that the end with the most stress is towards the chamber since the muzzle end acts as the end of a lever arm?

pic for reference:

See those holes in the hand guard? Do that all the way around the tube with the rows staggared.

Yeah it does seem the way to go, it seems it would be no less strong than a Troy TRX rail with round holes, even with the top slot cut.

Although the Troy does have somewhat of a flange around each of the holes for more strength. On the other hand, this tube is steel, not aluminum, so likely the same or stronger right?

The thought occurred to me to chop the ends off and attach them to a carbon fiber tube but not trying to sink that much $$ into this.

You are correct on where most of the stress is located. It increases towards the nut. You will start to lose strength as soon as you put the first hole in it. You can minimize the amount of loss by more holes towards the muzzle, decreasing as you move towards the nut.

The issue will not be strength but deflection. The structure of the tube is narrow making it deflect a lot when slung up tight. As you remove material, deflection for the same force will increase.

Not sure what the project is for but it is odd using a free float tube for rifles that are heavy for a light rifle project.