Recently had somewhat of an experience with an AR hand guard purchased thru
Saskatoon Gun Works. Darren went above and beyond for this and I owe it to him for all to know. Anyway bought the Aero Atlas S-one hand guard as a part of an order we had built up over the phone. Got the order the NEXT day and out of pure excitement I called him to thank him for the excellent service. He almost immediatly asked for me to pull the hand guard out, spin on the barrel nut and see it the hand guard would line up. Of course the Crypto being built the way it is and its two retaining pins + block up front, its slightly wider upper and the base of the top pic rail it was unable to fit. Darren had two options he sent my way instantly. Money back or send him my upper and free of charge he would put the work in to make it fit and if not still refund the money spent. Took me a couple minutes to decide as I love to tinkering with my projects, however I took the chance to trust him in being as meticulous as I would be in making this fit perfect. Darren nailed it!! Atlas fits my crypto as if it was designed for it. Buying that hand guard "blind" / not seeing in person was a risk on its own, however the design caught my eye.
I don't know what style of hand guard you're after. I am not a precision shooter, tho I would assume you're probably not after the lightest unit you can get on there
The price of this unit, it comes with its own barrel nut tool and the weight and shape all caught my eye. I ended up buying 2, and the other will have to be my project. Darren invested a lot of time into making this fit, he did a hell of a job and I love this hand guard!
https://www.saskatoongunworks.com/atlas-s-one-handguard-m-lok-aero-precision.html
Saskatoon Gun Works also has this unit which I'm pretty sure we came to agreement would not need to be modified. However the profile of it is "huge" in my eyes. This unit you also would need to purchase a seperate barrel nut and whatever tool needed.
https://www.saskatoongunworks.com/ar15-quantum-m-lok-handguards-aero-precision.html
Lastly. I will say I have had good luck with the TNA / Dino defence and GP Seller 416 dealer (or something like that) and the Chinese MLOK unit they sell. Have it in 15" and 17" and they come with there own barrel nut and are pretty sturdy along with being cheap around $160.
https://truenortharms.com/ar15_default_store_view/super-m-lok-handguard-easy-install.html