Hi David and welcome back. Yes Sir, they will work no issue and are considered top tier magazines for the AR platform including the Ruger AR-15 5.56 upc:736676085002. Cheers, stay safe and enjoy!

Good evening to you!! Yes the Magpul Magazines upc:873750006178 will fit the Ruger AR-15 5.56. The Magpul magazines are compatible with standards set by the US Military for magazines. There will be no problem working in a Ruger AR-556. Hope this helps. Have a good rest of your day.
🇺🇸🇺🇸 'Merica' 🇺🇸🇺🇸

Yes, Magpul AR/M4 GEN M2 and GEN M3 magazines are designed to fit and function properly in the Ruger AR-556 and other standard AR-15 platforms. These magazines are compatible with STANAG 4179 standard platforms, specifically chambered for 5.56x45 NATO or .223 Remington, ensuring reliable, high-capacity, and durable feeding.