Sorry to revive, but I've taken somewhat of an interest in the IAR.
Anyways, some updates to the developing IAR platform:
FNH, Colt, and H&K were selected as the finalists for the IAR platform, each receiving development contracts. FNH's entry is basically a scaled up SCAR which can operate from an open or closed bolt. Colt's offering is a scaled up M4A1, still using direct gas impingement. Lastly, H&K's entry is a scaled up 16.5 inch barrel HK416.
Somewhat unsurprisingly, H&K's IAR was selected. The Colt IAR uses direct gas impingement and thus would have the same reliability issues of the M16 platform, and the SCAR has different ergonomics than the M4/M16 platform in service, looks different (enemies could identify a soldier carrying a different weapon than the rest of the fire team), and also the HK416 was selected over the FN SCAR-L by the JSOC while the rest of SOCOM is fielding the SCAR-L. The H&K IAR has similar ergonomics to the M4/M16 platform and thus will not be a huge change for those using the IAR, but it also uses a gas piston system which generally has less reliability problems than direct gas impingement.
I myself am fairly excited about the IAR entering service. I think it actually has a role in a fire team as a weapon which can lay down suppressing fire when necessary but also can be used similarly to a normal combat assault rifle and be almost as mobile as one too. Also, there have been developments on a 100+ round drum/dual drum magazines, such as this one from Armatec: defense review.com/armatac-saw-mag-also-written-sawmag-150-shot-double-drum-magazine-for-usmcs-hk-iar-infantry-automatic-rifle-for-mobile-infantry-fn-m249-sawlmg-look-out (remove space between defense and review, apparently I can't post links until 10 posts made) . Interestingly, the article title states "FN M249 SAW/LMG Look Out!". My impression was that the IAR would supplement the SAW from what I've been reading, however, a magazine-based replacement of the SAW wouldn't be too bad an idea in my opinion.
Anyways, through reading the last 12 pages of discussion, I wanted to discuss and debate some of the comments made:
F-15 Eagle, you constantly state that 30 rounds isn't enough. While that may be true in some extenuating circumstances, a 30 round magazine being fired in bursts should be just fine for suppressing fire. For example, with 5 round bursts, it would go like: burst, burst, burst, burst, burst, burst, magazine reload, burst, burst, etc. Reloading a magazine is much easier than replacing a belt or having an assistant constantly adding on more segments to the belt.
Also, you state the need for volume of fire, yet in many posts you seem to be praising the Mk.46 Mod.0 as a replacement for the current FN Minimi/M249 SAW. You do know what the Mk.46 Mod.0 is, right? The Mk.46 Mod.0 is a smaller version of the current FN Minimi/M249 SAW in service right now: world.gu ns.ru/machine/mg17-e.htm (remove spaces again). The Mk.46 Mod.0 wouldn't solve any mechanical problems that the SAW has in exotic environments (IE, desert environments) right now because it's the same gun, just with a shorter barrel and no magazine feed capability, which leads to my next point. The barrel of the Mk.46 Mod.0 is just about 16 inches long (406mm, rough conversion 2.54:1 cm:inch ratio=15.98 inches) rather than the usual 18.3 inch barrel on the M249. Smaller barrel=less ability to sustain fire no? So why do you support using the Mk.46 Mod.0 as a SAW replacement? Not to mention less accuracy and muzzle velocity which leads to reduced range. Lastly, the H&K IAR has a 16.5 inch barrel and is magazine fed. Thus, it has similar (well, even longer) barrel length to the Mk.46 Mod.0, sounds like similar capabilities, no? Furthermore, the H&K IAR is magazine fed, the M249 can be either magazine or belt fed, and the Mk.46 Mod.0 only has belt feed capability (no mag feed for reduced weight). With new dual drum magazines coming out with 100+ round capacity (like the one I linked earlier in my post), it may be beneficial to carry magazines rather than belts. As belts are far more unwieldy and take much longer to reload (or have an assistant attaching additional ammo onto the current belt). Replacing the SAW currently in service with the Mk.46 Mod.0 doesn't seem like a smart idea to me, even in terms of what seems to be your primary parameters for a LSW, volume of fire, the Mk.46 Mod.0 will not offer as much volume of fire as the current SAW. Furthermore, reduced accuracy and range, and the same reliability problems make it tough to recommend the Mk.46 Mod.0 as a SAW replacement.