That would be a huge range in weight. I'm not sure how anyone would give you an accurate depiction of what you are looking for considering an SCR-11 build could incorporate a huge array of different options that could directly effect weight. What are you trying to build? It's probably within a pound of any other 18" 5.56. it all depends on......well, a lot. Here is an example of the number of options youd be taking into account with the build....
SCR-11™ Rifle
Base Price: $2699
Upper Receiver: SCR-11 Upper Receiver
- Machined 7075-T6 billet aluminum side charge upper receiver
Lower Receiver: SCR-11 Lower Receiver
Machined 7075-T6 billet aluminum lower receiver
Receiver Finish: Matte Black
Receiver Color:
Matte black anodized receiver set and hand guard.
Caliber: .223/5.56 NATO
Barrel: 18" .223/5.56 NATO JP Supermatch™ cryogenically treated stainless steel barrel, 18" length ● 1:8 twist ● medium contour
Barrel/Comp Finish:
Polished stainless, Barrel polished and blended to muzzle treatment: JPTRE-412S, JP Standard-Profile Compensator, 1" x 2.25", .281 Exit, Stainless
Comp Attachment method:
The muzzle treatment is attached to the barrel via thread, timed and blended for seamless transition. No welding or pinning is used.
Hand Guard:
JP Modular Hand Guard, rifle length (12.5” OAL), for AR-15/M16 type rifle
Gas System:
JPGS-3
JP Adjustable Gas System Picatinny rail .750" bore Black Aluminum
Heat Sink:
Black JP Thermal Dissipator™
The JP Thermal Dissipator™ far exceeds traditional fluting for transferring heat from the barrel.
$75
Buttstock:
ACE-ARFX stock, black
Operating System:
JPBC-2
JP Full Mass Stainless Carrier with JP Enhanced Bolt
Operating Spring:
JP Custom Polished Spring and Standard Mass Buffer
Trigger Weight:
3.0-pound JP competition trigger
Grip: Hogue grip, Black
Operating Controls:
JP ambidextrous Safety