Rainier Arms Forged A4 Mil-Spec Upper Receiver AR15 AR-15
Rainier Arms flattop upper receiver is carefully machined to mil-spec to serve as a great foundation for a quality AR rifle.
These uppers are "T - marked" engraved and have extended M4 feed ramps.
- Made from 7075 - T6 aluminum
- Type III hard coat anodized
- Matte black finish
- Dry lube coating: Inside to reduce wear and adds lubricity
- "T - Marked" engraved
- M4 Feed Ramp
Which is better, Forged or Billet Uppers?
This is very commonly asked and often stirs debate. Forged aluminum offers an improvement in strength. Forged pistons are exclusively used in high performance motors - not billet. And forged aluminum wheels are stronger and lighter - spec on many cars now. Not cast - and not billet. Billet is usually machined with extra, nice to have, features like integral winter trigger guards, flared magwells, whatever. Worth the high extra $? It's user preference, but I would build with a forged receiver over a billet receiver any day due to the lower weight, higher strength, and lower cost.
Which is stronger, Forged or Billet Uppers?
Forging aluminum workhardens or improves the material. Grain structure flow will always be optimized in a forging for the weakest section of the design parameters. This enhances strength over Billet. Billet uppers can be built as strong in flex as forged - but the cross section is thicker, and the overall part will weigh more. They don't make billet carabiners (climbing gear) for a good reason. Forgings are STRONGER, but Billet is strong enough with additional material.