I did a thread almost 2 years ago about cutting the picatinny off of my factory swat rails

https://www.ar15.com/forums/general/Which-machine-shop-to-modify-a-quad-rail-with-MLok-slots-or-KeyMod-UPADTE-Found-one/5-1968728/

I finally did it, I did my P556 first and it turned out awesome. After the cut there is a ton of meat left and the weight loss could be readily felt (I didnt weigh it unfortunately).  The bottom rail is cut to match an aluminum Magpul MLOK rail section so I can use the pictured Stark AFG (until I finally get around to a Form 1 and can use an MLOK VFG)

Before



After





Still needs coated though

Dude, please show us the finished product. I'll gladly pay you to slim these pig rails down...

Slimmed it down pretty good.

Yes please, I've got a ruger sr556 that i wanted to do this with.