Gunsmithing Question for Maxim Defense PDX/MDX owners

[MO Fugga]

I ended up with a different brand of 5.5" barrel in .300 blk, and the Hate Brake. Their site says the MDX handguard only works with their upper. Is it because of the small tab in the rear that could be cut off? Warranty be damned, this could be made to fit? Thanks.

 

[D46Infinity]

It’s because the handguard has the tab to lock to the upper as well as the rail is at the HK 416 height. It’s about .233 higher than a standard AR is what I have seen measured.

I can check tomorrow as I have got a PDX upper to work on this week.