The HK IAR is apparently a heavy barreled HK416 with bipod and standard closed bolt operation. It will most likely have a drum mag possibly similar to this:
U.S. Marine Corps Selects Heckler & Koch Infantry Automatic Rifle (HK IAR) Candidate as Replacement for FN M249 SAW/LMG
By David Crane
Marine Times (a.k.a. Marine Corps Times) is reporting on the U.S. Marine Corps (USMC) selecting the Heckler & Kock Infantry Automatic Rifle–or HK IAR, for short–to replace the FN M249 SAW/LMG (Squad Automatic Weapon/Light Machine Gun). The HK IAR is a 5.56×45mm NATO (5.56mm NATO) gas piston/op-rod AR-15-config carbine that’s based on the HK416 carbine/SBR (Short Barreled Rifle) platform.
The IAR is designed to give FN M249 SAW/LMG-type capability in a lighter-weight rifle/carbine package that’s not only easier for mobile infantry warfighters to carry and employ/deploy than an M249, but also give them an similar weapons signature to the rest of the fire team/rifle squad, so they’re harder to identify, and thus target, by enemy forces. The enemy will tend to go for (i.e. kill) the machine gunner first, in order to render the fire team less lethal and effective. The IAR camouflages the infantry automatic rifleman, and his ballistic capability.
So, in that sense, the Infantry Automatic Rifle is a decent concept. On the downside, some Marines are concerned about the reduction in firepower vs. the M249, since the IAR is mag-fed not belt-fed, and therefore isn’t designed to operate with a 200-round drum/ammo container. Currently, the HK IAR can utilize standard 30-round 4179 STANAG AR-15/M16/M4/M4A1 box magazines, the 100-shot Beta C-MAG double drum mag, and MWG 90-Rounder drum mag, although new 100-150-shot magazines are reportedly being developed by industry for the IAR.
DefenseReview isn’t really a big fan of the Beta C-MAG, and we wouldn’t want to have to rely on it in a dynamic infantry combat environment. It’s simply not as reliable as we’d like under adverse conditions and high round count, and it requires graphite powder lubrication to run properly. We do, however, like the MWG 90-Rounder for certain applications, even though it’s not perfect and could use a bit of a redesign, in our opinion. The MWG 90-Rounder is reliable, however, provided it’s utilized with a quality rifle/carbine platform like the Ferfrans SOAR AR SBR/subcarbine series.
The HK IAR weighs 7.9 lbs empty. Barrel length is 16.5 inches (16.5″).
The HK IAR beat out the Colt IAR and FN IAR candidates for the Marine Corps IAR contract. According to Marine senior gunner and Chief Warrant Officer 5 Jeffrey Eby, The H&K IAR “was truly the best in the class on multiple levels and will finally allow the billet ofautomatic rifleman to be performed as intended without the disruption of the squad integrity that the M249 created.” Eby says that IOT (Initial Operational Testing) is scheduled to take place from January to May 2010 in Panama, at theMarine Corps Mountain Warfare Training Center, and the Marine Corps Air-Ground Combat Center in California. “If successful and awarded full-rate production approval, then we should see initial operational capability by late summer 2010,” Eby said.
So, is the Infantry Automatic Rifle (IAR) a good idea? Yes and no. It’s a good idea to give warfighters a carbine/SBR with machine gun-level full-auto fire capability. However, all one really needs to do to give any direct-gas-impingement (DGI)/DI gas or gas piston/op-rod AR carbine or SBR IAR/LMG-type capability is stick a heavymachine gun barrel on it and a Ferfrans Rate Reduction System (RRS) in it. That’s pretty much it, and it’s a much simpler and less-expensive solution. The RRS reduces the cyclic rate of fire below the 700 RPM threshold, which aids in weapon controllability and simultaneously reduces barrel and weapon heating and stress on all the weapons critical parts. The heavymachine gun barrel better resists the heat generated by full-auto fire.
After a year of speculation and commentary from pundits, myself included, the Marine Times reports that the H&K has won the competition and that their entry will enter production next year ...
The Marine Corps has selected the infantry automatic rifle made by Heckler & Koch as the weapon that will replace the M249 Squad Automatic Weapon in infantry fire teams, a senior service official told Marine Corps Times on Wednesday.
The H&K IAR “was truly the best in the class on multiple levels and will finally allow the billet of automatic rifleman to be performed as intended without the disruption of the squad integrity that the M249 created,” Chief Warrant Officer 5 Jeffrey Eby, the Corps’ senior gunner, said in an e-mail.
Despite what is said in the above quotation, I do not think that the SAW is being replaced outright. The Marine Times has at times reported that the SAW would be replaced with the IAR, and at other times reported that it would augment the IAR, not replace it ...
The plan is to buy 4,100 IARs and reduce the number of SAWs in the Corps from 10,000 to 8,000, Cantwell said.
“We are still going to maintain SAWs in the company,” he said. “Only 2,000 SAWs will be replaced. The reminder will be kept as an organizational weapon for when commanders need them.”
The H&K entry was a modified version of their HK416 piston-operated AR-15 rifle. Unlike the Colt and FN entries, it is said to fire only from a closed bolt. Given the lack of an open-bolt fire mode I had presumed it was the least likely choice for an automatic rifle.
Presumably it is fitted with a heavy barrel, like H&K's previous, and commercially unsuccessful, attempt at the automatic rifle: the MG36. The Marine Corps has been reporting the weight of the 16.5" barreled H&K IAR as being 7.9 lbs. This is not possible as a standard 16.5" barreled Hk416 weights in at 7.84 lbs. I also think that the photo of the H&K IAR shown by the Military Times is that of a standard HK416.
I have contacted H&K to see if they are willing to publicly acknowledge if they have won. If they do, I will endeavor to get the specs of the new weapon.
UPDATE: I have written a follow up blog post here.
Many thanks to Mark and Matt for sending me the news.