The HK MR762 A4 SBR is Heckler & Koch’s large-frame semi-automatic rifle in 7.62x51mm, built with a 13-inch barrel (HK part no. 81001054). That barrel length and a shoulder stock make it a short-barreled rifle, putting a full-power cartridge in a package that is far shorter than a standard battle rifle. It feeds from 20-round magazines and uses an ambidextrous safety, so it runs the same from either shoulder. It is a strong choice for a shooter who wants 7.62 NATO power without the length of a 16-inch or longer rifle.

Key Specifications

• The chambering is 7.62x51mm, a full-power rifle cartridge.
• Barrel length is 13 inches, short enough to make this a compact short-barreled rifle.
• Magazine capacity is 20 rounds, standard for a large-frame 7.62 rifle.
• The safety is ambidextrous, so left- and right-handed shooters operate it the same way.
• The action is semi-automatic, one shot per trigger pull.
• The configuration is a short-barreled rifle, a shoulder-stocked rifle with a barrel under 16 inches.

Frequently Asked Questions

Do I need ATF approval to buy this? No. As of October 9, 2026, ATF no longer requires Form 4 approval, registration or a tax stamp for short-barreled rifles. It transfers on a Form 4473 with a background check through a Class 3 (SOT) dealer. State and local laws still apply. Taking an SBR across state lines still requires an approved ATF Form 5320.20.

What caliber does it fire? The MR762 A4 SBR is chambered in 7.62x51mm.

Is the safety ambidextrous? Yes. It has an ambidextrous safety.

Buy the HK MR762 A4 SBR, 7.62x51mm, 13-Inch

A 13-inch 7.62 rifle from HK is a rare combination of power and compact size. As of October 9, 2026, this short-barreled rifle transfers on a Form 4473 with a background check at your Class 3 (SOT) dealer, with no Form 4 or tax stamp; state and local laws still apply. Order through Heckler & Koch‘s short-barreled rifles lineup and our Lubbock, Texas team will handle the transfer as soon as it is available to ship.