Heckler & Koch MR556A4 Upper Receiver Kit 5.56 16.5 Black

What happens next

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Need a quick answer before you buy? We are happy to help with fit, compatibility, and what to expect next.

1. Place the order with confidence. Live pricing and availability are shown right here on the product page.
2. Watch for confirmation. We will confirm the order and follow up if anything needs attention.
3. Get help fast. If you want a second set of eyes before checkout, contact us and we will point you in the right direction.

If you are comparing options or checking fitment, reach out before you buy. We would rather answer the question now than fix the wrong order later.