Dirty Bird AR-15 Forged Multi-Cal Receiver Set + SRMS Handguard - Midnight Bronze, 12.7"

Dirty Bird Industries SMRS (Slim M-LOK Rail System) Handguard:Tough Machined from aircraft grade 6061-T6 aluminum extrusions. Anti-rotation tabs. Type 3 hard anodizing or Cerakote(TM) sprayed at 1 mil thickness per spec.Versatile M-LOK attachment slots on all sides (except top) 1913 Picatinny top rail with shaved and beveled center section. Raised QD attachment points at the 3 and 9 o'clock positions. Snag free design with smooth, uniform octagonal surface ideal for accessory attachment or application of specialty coatings or patterns.Practical Aircraft Grade aluminum barrel nut. In our tests, the aluminum barrel nuts are just as effective when torqued to spec. Additionally, the weight savings enable us to utilize a longer barrel nut design which means more surface area at the attachment point without adding unnecessary weight. Compatible with most known low profile gas blocks.Straight Forward Installation No frills clamp-on style installation using only a 1-3/16 Crow's Foot wrench and 5/32"" Allen key. Barrel nut does not requiring timing with the gas tube. No shims required.The end result is a great looking, zero compromise handguard suitable for a wide variety of builds.Interior Diameter1.35"" ID1.7"" Maximum Vertical ID (for considering vertical height of gas blocks)Dirty Bird Industries AR-15 Forged Multi-Cal Lower Receiver:Quality Materials, Durable Finish 7075-T6 Forgings Precision machined on state of the art CNC equipment with quality and tolerance checks throughout the machining process Matte black Mil 8625 Type 3 Class 2 hard-coat anodizingMaximum Compatibility ""Multi-Cal"" markings for compatibility with many different caliber uppers Machined to Mil-Spec dimensions Compatible with all standard AR-15 components and magazinesDirty Bird Industries AR-15 Stripped Upper Receiver:Builders know that not all mil-spec forged upper receivers are created equal. Sub-par forgings suffer from pitting and structural defects, poor anodizing can result in a purplish or chalky finish that doesn't last and sloppy matching can result in mis-sized lugs, burrs or other machine marks.The Dirty Bird Industries AR-15 Stripped Upper Receiver is precision machined to M16/M4 Mil-Spec using top quality forgings (NOT the rejects). They are then finished with a uniform Mil-Spec Type III hardcoat anodizing and laser etched t-marks. These units are quality checked throughout the process to ensure consistent quality from unit to unit.You have Dirty Bird's word that these uppers will be free from excessive pitting, machined to spec and finished with quality (not purple or chalky) hard coat anodizing.Features: 7075-T6 Aluminum Forgings (forge marks may vary) M4 Feedramps .250 takedown pin holes Laser etched T-marks Port Door (Dust Cover) and Forward Assist not includedNOTE: Cerakoted options will not have laser etched t-marks100% American MadeDirty Bird Industries' Limited Lifetime Warranty