AR15 Handguard Perspectives and Complaints UPDATE

[LRRPF52]

UPDATE:
Breaking the handguard down into its different components and intended use, I'd like to hear people's feedback on the various design points.

I. Handguard attachment method to the upper receiver

• Standard Mil Spec barrel nut and handguard cap attachment, non free-floated, nut requires armorer's wrench with teeth
  
• Threaded free-float nut with holes for gas tube with external threads for featureless straight tube
  
• Handguard clamps to upper receiver 1913 rail, free float
  
• Cylinder free float nut with flats for common wrenches, handguard clamps to nut
  
• Cylinder free float nut with wrench flats, handguard screws to nut with set screws
  
• Non Mil Spec upper with independent handguard attachment with set screws, with wrench flat barrel nut underneath that doesn't contact
  
• Non Mil Spec upper with independent barrel nut and pipe fitting style screw attachment of face to face
  
• Monolithic welded handguard to upper
  
• Monolithic billet
  

II. Handguard shape and human interface

• Conical bakelite prototypes
  
• Triangular 2-piece with handguard cap
  
• Ribbed A2
  
• Ribbed carbine
  
• Cylinder aluminum tube
  
• Ribbed dual heat shield M4
  
• KAC RIS/RAS 4x1913 rails
  
• SIR
  
• 1913 12 o'clock, streamlined tube with vent holes
  
• 1913 12 o'clock, streamlined, with 3,6,9 shortchanged rail sections up front
  
• 1913 12 o'clock, octagonal cross section
  

III. Handguard adaptability to sling attachment, aiming and illumination device interface

• Sling attachment via QD sockets, how many QD socket options
  
• White Light attachment and activation options (pressure switch vs tailcap)
  
• IR Laser Aiming Module and activation with or without White Light/IR filtered white light
  
• Bipod attachment ease of mounting, stud vs 1913 clamp-on, swivel post

IV. Handguard resistance to deviation from alignment with the barrel



V. Handguard Material

• Wood
  
• Bakelite
  
• Glass nylon with aluminum heat shields
  
• 6061 Tubular aluminum
  
• 6061 aluminum extrusions
  
• Al/Mg alloy
  
• Al/Li alloy
  
• Billet 7075T6
  
• Billet 6061
  
• Carbon fiber