AFG 4 inch handguard

I modified the original model in FreeCad, in order to make it shorter and cut out a slot so that it would fit my M-Lok handguard with only one M-Lok slot. I also changed the front M-Lok locator tabs to something more-closely resembling the official Magpul locators.

Here is the 4-inch rail that this mounts properly to: https://ar15discounts.com/products/nbs-free-float-m-lok-handguard/