FYI : Before you buy! Many AR15's are polymer lowers and uppers

[Boarman03]

ATI (American Tactical Inc.)

ET Arms

Kaiser US Shooting Products | Ultralight Polymer X-7 Fusion AR-15 Carbine ...

Tennessee Arms Company lowers

FMK AR-Extreme Polymer AR-15 Lower, FDE

Also 

ROCK ISLAND ARMORY TM22 LITE .22 LR 18" BA

Just to name a few. Many sites are NOT describing what material the AR15 is made out of so do your homework and research before you buy.

Most manufacturer's polymer AR15's void the warranty if you make any changes. But more importantly are some of the documented problems with polymer vs. aluminum.

😁

 

[thegunsmith2506]

I have owned several polymer lowers and never had an issue. Its good to know what you are buying for sure. 

[Boarman03]

36 minutes ago, thegunsmith2506 said:

I have owned several polymer lowers and never had an issue. Its good to know what you are buying for sure. 

ATI had a problem with the lowers cracking at the rear pin. 

There have been reports of some uppers cracking. I personally have a problem with a plastic/polymer upper with all of the movement and pressures. Billets stretch and forged have greater strength, but can fragment. Plastic/polymer? I'm not sure I want to know.🤣

I'm glad you have not had any issues, but the prices are about $50 to $100 dollars difference and the longevity I believe definitely goes to aluminum, as well as flexibility in customization and possibly safety. IMO of course. But I could be wrong.