Tactical tuna is a term I’ve heard used to describe three different rifles. The first being the FS200, a bullpup from FN; the second being the Beretta ARX 160; and the third being the subject of today’s article, the XM8. The reason the name sticks is the odd front ends these guns carry that are more round than brick or pipe-like in nature. They all tend to look a bit bulky and plasticky with their rather unique designs.

Of all these three tactical tuna rifles, only one never really made its way to the civilian market, and that’s the HK XM8. HK has always been gun shy, for lack of a better term, in releasing long guns in the United States. A long time ago, they got bit quite hard by gun control and lost a ton of money, so they’ve been reluctant to do so since.

Nevertheless, the XM8 garnered a fair bit of pop culture popularity in the mid-2000s. If there was a tactical shooting video game, you could bet a gamer’s Cheeto dust-covered finger that the XM8 popped up in the game one way or another. At the time, the rifle looked quite futuristic and was constantly in television series on the future of warfare.

Where the XM8 Came From

Way back in the mid-90s, the United States military and HK were working on a weapon called the Objective Individual Combat Weapon (OICW). Do you know what lots of rifles have under-barrel grenade launchers? Well, the OICW was the opposite; it was a grenade launcher with an under-barrel rifle.

The OICW program is an article for another day, but this is where the XM8 originated from. That under-barrel rifle would become the XM8 series of firearms. The XM8 quickly gained a little steam with the United States military. Although Colt threw a fit and the program was delayed then opened up for other industries to submit samples to.

The HK XM8 went through testing on and off throughout the years. The rifle tested extremely well with very few stoppages when compared to the M4, the SCAR, and HK 416. When firing 60,000 rounds, the XM8 had only 127 stoppages compared to the M4’s 307. The SCAR had 226 stoppages, and the HK 416 had 233 stoppages.

The XM8 might’ve tested well, but the U.S. Army didn’t see a big enough improvement over the M4 series to adopt it. The testing caused the Army to look into how to improve the M4, especially the magazines, rather than adopt a new rifle.

What Exactly Is the XM8

As most of you know, the XM8 began life as an assault rifle. The weapon utilized a short-stroke gas-piston system that’s a bit more common than the old direct impingement guns. HK used a hefty amount of polymer in the design of the rifle with the intent to minimize weight. The XM8 is based on the older HK rifle, the G36, and can be considered a G36 derivative.

Various models of the XM8 incorporated built-in optics that offered 3.5X magnified optics and 1X red dots. However, this feature seemed to wane in popularity, and a Picatinny rail was added to the carry handle to allow the user to attach their optic of choice.

One fascinating development was the PCAP attachment system. PCAP stands for Picatinny Combat Attachment Points. This was a modular rail system similar to M-LOK or Keymod and allowed users to mount rails exactly where they needed them for accessories.

The XM8 started as an assault rifle, but HK envisioned it as an entire weapon system. The various incarnations of the rifle included the following:

• XM8 Rifle – Rifle variant with a 12.5-inch barrel and compatible with an under-barrel grenade launcher.
• XM8 Carbine – Super compact option with a nine-inch barrel and a collapsing PDW style stock.
• DMR Variant – XM8 with a 20-inch barrel and 3.5X or 4x optic combined with a bipod.
• Automatic Rifle – XM8 with a 20-inch barrel, bipods, and an optional 100 round drum.

Post Army Success

As mentioned, the U.S. Army decided that the rifle wasn’t worth the investment. Instead, it worked to improve the M4 series of rifles, and as we know now, the M4 still rules in special ops and with conventional forces. The Royal Malaysian Navy’s special ops unit PASKAL adopted the XM8, and we’ve seen it fielded in Malaysian military parades (as shown in this article’s featured picture) but that’s about it.

The XM8 series of rifles isn’t necessarily dead, but it’s got a foot in the grave. HK has moved on and thrown its weight behind the HK 416, which has seen a lot of success with America’s most elite units, including Delta Force and SEAL Team Six.

The XM8 represents an interesting time in weapons design. While the rifle didn’t succeed, the ideas behind it have become rather mainstream. This includes modular rails and do-it-all rifles. The Marine Corp’s M27 is an HK416 that’s being used as an automatic rifle, assault rifle, and DMR, so it’s not too far from the XM8’s ideas.

What does the crowd say? What do you think of the XM8? If you want one, you can pay a pretty penny to Tommy Built to get your own built, but other than that, it’s a pipe dream.