Here are factory contact sites that can help with current production firearms.

Armalite (Armalite.com, 623/780-1050).

Armi Sport di Chiappa (ChiappaFirearms.com/parts.php, 937/835.5000).

Barrett Firearms (store.Barrett.net).

Benelli USA (ShopBenelli.com/parts.html).

Beretta Corp. USA (Beretta.com/en-us/spare-parts-1).

Browning Arms Co. (Browning.com/support/parts-service.html).

Charles Daly (CharlesDaly.com/parts.php).

CimarronFirearms (CimarronFirearms.com/accessories/parts.html).

CMMG (CMMG.com).

Colt’s Manufacturing (Colt.com).

Cooper Firearms (CooperFirearms.com/pages/options-and-accessories).

CZ-USA (shop.CZ-usa.com).

Glock Inc. (store.teamglock.com/gun-parts).

Heckler & Koch (us.hkwebshop.com/hkstorefront/?site=hk).

Hi-Point Firearms (Hi-Pointfirearms.com).

Ithaca Gun Co. (IthacaGun.com/internal-parts).

Kimber Mfg. Inc. (store.KimberAmerica.com).

Marlin Firearms (MarlinFirearms.com).

O.F. Mossberg & Sons (Mossberg.com/store/parts.html).

Pedersoli Davide & C snc (shop.Davide-Pedersoli.com/en/14-spare-parts)

Perazzi Inc. USA (Perazzi.it/en/perazzi-usa.php).

Remington Arms Co. (RemArms.com).

Ruger Firearms (Ruger.com/service/partsService.html).

Savage Arms Inc. (SavageArms.com).

SIG Sauer Inc. (SigSauer.com/parts.html).

Smith & Wesson (store.smith-wesson.com/parts-and-magazines)

SpringfieldArmory (store.Springfield-Armory.com/Shop/pc/home.asp)

Taylors Firearms (TaylorsFirearms.com/accessories/parts.html).

Thompson Center Arms Co. (Tcarms.com).

Traditions Performance Firearms (TraditionsFirearms.com/support/product-schematics).

Uberti (ShopUberti.com/parts.html).

Walther Arms (WaltherArms.com/parts).

Weatherby Inc. Weatherby.com/shop-home/gun-parts).

Winchester Repeating Arms (WinchesterGuns.com/support/parts-service/parts.html).

https://funshoot.substack.com/p/gun-part-sources