$2,649.00
2 in stock
Online inventory may differ from in-store availability.
NOTICE: This item is subject to shipping times of 10-12 days due to brand shipping logistics.
Orders are processed quickly so your item gets moving as soon as possible.
Trusted checkout with industry-standard protection.
Keeping Traditions Alive Since 1953
Secure Transactions provided with 
This is the real deal from Heckler & Koch: a complete factory MR762 A4 upper receiver kit that lets you convert or refresh a compatible 7.62x51mm rifle into HK's piston-driven A4 configuration. Instead of the direct-impingement gas tube found on most AR-style guns, the MR762 A4 runs a short-stroke piston and pusher rod. The payoff is that hot carbon and waste gases stay out of the receiver, so the action runs cooler, cleaner, and with less wear on the internals over time. It's the same core design that made the HK417 a favorite among elite military and law enforcement users, and it's assembled in the USA using US and German-made components.
The heart of this kit is a 16-inch cold hammer forged steel barrel with a 1-in-7 twist, threaded 5/8×24 so you can run common .30-caliber muzzle devices or a suppressor mount. Up top you get an extended Picatinny rail for optics and iron sights, plus a free-floating M-LOK handguard with rail sections and QD points for slings and accessories. The adjustable gas regulator is a genuinely useful touch here, letting you dial the action in for suppressed or unsuppressed shooting so the rifle cycles the way you want it to.
Since this ships as a complete upper with the bolt carrier group, buffer, and buffer spring included, it's close to plug-and-play once you have the right lower. Keep in mind this kit is designed to mate with an MR762 lower receiver. It's backwards compatible with older A1 MR762 lowers, though the A4's ambidextrous magazine and bolt catch releases only function on an A4 receiver. For anyone chasing German build quality and piston reliability in a 7.62 platform, this is about as close to the source as you can get.
This kit is built to mate with an MR762 lower receiver. It's backwards compatible with older A1 MR762 lowers, but the A4's ambidextrous magazine and bolt catch releases only work when it's running on an actual A4 receiver. It is not a general AR-10 upper that drops onto any 7.62 lower.
The big difference is the operating system. Instead of routing hot gas back into the receiver through a gas tube, the MR762 A4 uses a short-stroke piston and pusher rod that keeps carbon and heat out of the action. That translates to cooler, cleaner running and easier maintenance, which is the same design principle behind the battle-proven HK417.
Yes. The 16-inch barrel is threaded 5/8×24, which is the common thread pitch for .30-caliber muzzle devices and suppressor mounts. The adjustable gas regulator is also a real advantage here, letting you tune the action for suppressed or unsuppressed shooting so cycling stays smooth either way.
The kit includes the complete upper receiver and barrel assembly, the bolt carrier group, and the buffer with spring, and it ships in an HK soft case. You'll still need a compatible MR762 lower receiver to build out a functioning rifle. Optics, sights, and a muzzle device are separate additions based on your setup.
| UPC | 642230274365 |
|---|---|
| Manufacturer | |
| Manufacturer Part Number | 51001892 |
| Action | |
| Barrel Length | 16" |
| Caliber/Gauge | 7.62x51mm |
| Product Type | Accessory-Uppers |
| Shipping Weight | 0.0 |
You must be logged in to post a review.
Reviews
There are no reviews yet.