The Trigger Supply Rainbow PVD BCG is the build piece that makes your AR-15 stand out without sacrificing anything on reliability. Physical Vapor Deposition coating over high-polished components produces the iridescent rainbow finish — every unit catches light differently. Under that finish is a fully spec'd Carpenter 158 steel bolt, M16 cut carrier, mil-spec gas rings and O-ring, and magnetic particle inspection on every bolt before it ships.
It looks like nothing else on the market. It runs like a mil-spec BCG should.
What Makes It Different
Physical Vapor Deposition deposits an extremely thin, molecularly bonded coating that produces the iridescent rainbow color. Harder than phosphate, does not chip or peel. The finish is applied over high-polished components — the polish is what gives the reflection, the PVD is what gives the color and durability.
Every carrier and bolt surface is polished before PVD coating. The result is a mirror-quality finish that no standard BCG produces. High polish also reduces friction at contact surfaces for smoother cycling — form and function together.
Features
- Rainbow PVD finish — Physical Vapor Deposition iridescent coating over high-polished components. Harder than phosphate, bonds at molecular level
- Carpenter 158 steel bolt — the original mil-spec bolt alloy specified by the US military. Chrome-moly-vanadium formulated specifically for bolt lugs under repeated firing stress
- Magnetic particle inspected (MPI) — every bolt inspected for internal defects before leaving the factory. The most reliable non-destructive testing method for bolt integrity
- M16 full auto cut carrier — heavier carrier profile for smoother, more reliable cycling. Functions as standard semi-auto in any mil-spec lower
- Mil-spec gas rings — standard mil-spec gas ring set for consistent gas seal and reliable cycling
- Mil-spec O-ring — standard mil-spec O-ring for gas retention
- 8740 steel firing pin — hard chrome finish — high-strength firing pin alloy with hard chrome plating for long-term durability
- 4140 steel cam pin and extractor — standard mil-spec alloys for both components
- 100% USA made — all components manufactured domestically
Component Steel Breakdown
9310 Steel — Rainbow PVD finish over high polish
Carpenter 158 Steel — MPI tested, Rainbow PVD finish
8740 Steel — hard chrome finish
4140 Steel — mil-spec
4140 Steel — mil-spec
Mil-spec — standard ring set
Mil-spec
Full Specs
| Caliber | .223 Rem / 5.56 NATO |
| Carrier Profile | M16 Full Auto Cut |
| Finish | Rainbow PVD over High Polish |
| Carrier Material | 9310 Steel |
| Bolt Material | Carpenter 158 Steel |
| Extractor Material | 4140 Steel |
| Cam Pin Material | 4140 Steel |
| Firing Pin Material | 8740 Steel — Hard Chrome Finish |
| Gas Rings | Mil-Spec |
| O-Ring | Mil-Spec |
| Inspection | Magnetic Particle Inspected (MPI) |
| Platform | AR-15 — all mil-spec uppers |
| Country of Origin | 100% USA Made |
The Trigger Supply M16 Full Auto Cut BCG ($149.99) is the workhorse option — same M16 cut, USA made, built specifically for FRT builds. The KAK Industry DBC K-SPEC BCG ($199.99) is the first BCG engineered specifically for forced reset triggers with a patented dead-blow weight system.
Frequently Asked Questions
What is PVD finish on an AR-15 BCG?
What steel is the bolt made from?
Is this BCG M16 cut?
Will the rainbow PVD finish hold up under hard use?
What makes this different from a standard mil-spec BCG?
Is this made in the USA?
Related Products
- Trigger Supply M16 Full Auto Cut BCG — USA Made ($149.99)
- KAK Industry DBC K-SPEC BCG — First FRT BCG ($199.99)
- Trigger Supply AR-15 Anti-Walk Pins ($24.99)
- AR-15 Buffers — H2, H2.5, H3 for FRT Builds
- Best FRT Triggers for AR-15 — 2026 Buyer's Guide
It is the buyer's responsibility to comply with all applicable local, state, and federal laws regarding firearm parts and accessories. Install by a qualified individual familiar with AR-15 platforms. Trigger Supply is a brand of TTT Innovations. 100% USA made.
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- weight is only 58 grams, under 3oz
-Length: 6 5/16"
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-This is the ONLY USA made gun smithing tool, gun cleaning tool, building tool, disable tool on the market.