In my opinion, the HK416 is not a good carbine. This is primarily due to its increased weight and recoil compared to the standard M4. The increased recoil, due to greater reciprocating mass and velocity, also increases the probability of damaged or loosened components. Furthermore, the already high cyclic rate of the 416 is increased further by the attachment of a silencer. As you can see in this video, the cyclic rate is simply too fast for even one of the strongest magazine springs on the market, the Lancer L5 AWM, to keep up with - resulting in a bolt-over-base malfunction (the rear of the case has not risen to the top of the magazine before the bolt face has returned to push a new round into the chamber). This is not an isolated incident, but a common occurrence with the multiple 416s I have witnessed exhibiting this problem.
If you are part of a unit or organization which must use the HK416, the best upgrade (short of replacing the entire weapon) would be to replace the receiver extension tube and buffer assembly with the Vltor A5 system (specifically the A5H4). Vltor tested the HK416 with the A5 and saw a reduction in cyclic rate from 1106 rounds per minute (stock, suppressed) to 973 rounds per minute (A5H4, suppressed).
If you cannot replace the receiver extension tube with the A5 system or get rid of the HK416s entirely, try using a Tactical Springs LLC/Springco "Red" action spring along with an H3 or heavier buffer.
Vltor Weapon Systems is probably best known for its excellent AR stock series: the original Modstock, the EMod (Enhanced Modstock), and the IMod (Improved Modstock). It's also known for the MUR and VIS AR-15 upper receivers and the CASV handguard. What many people don't know is that they make an astonishing variety of other products - to include PKM machine guns for foreign militaries, handguards, components, and stock adapters for other weapons, and so on. I considered myself familiar with their product line before a recent visit, but was, frankly, astonished to see how busy they have been, and how many new products they have.
This is pretty brief, as I'm preparing for a rather exciting adventure at the moment, but here's an overview of some unknown Vltor history, as well as photos of some of their new products.
One of the oldest Vltor products actually originated under ASAR, or Abrams Small Arms Research, before Abrams Airborne acquired Vltor years ago. That product is the CASV, which received several modifications for functionality and durability before being sold under the Vltor name. What you see here on the left is an original CAS-V prototype - made of titanium! - next to one of the newest CASV models, the split-level CASV-ELS.
The titanium prototype is rather heavy, as well as being expensive to produce, so the current aluminum CASV is a much more useful product to most end users. Thousands are currently in use by various US Navy units, among others.
Here are the new split-level versions, the CASV-ELS for carbine length ARs and the CASV-S for midlength ARs. The bi-level version allows for cowitness of optics mounted on the forward portion of the handguard. I've been using a CASV-ELS for several months, and love the profile of the newer handguards - they're ideal for "thumb-forward" support hand shooting.
Vltor still manufactures standard level CASVs, such as this CASV-M, shown with the optional front sight.
From oldest in the background to newest in the foreground, here's a glamor shot of some AR CASVs.
Vltor also manufactures quite a few M1A components, including the stock and handguard shown here. I was surprised to find that this weapon didn't feel too heavy and balanced quite well. Please excuse the poor framing of this shot.
Other AR type stocks are compatible with the tube shown here.
One weapon that definitely hasn't escaped the touches of Vltor is the SCAR. Here's a SCAR-H with the full treatment - a CASV-type handguard (extended beyond the factory handguard length, and allowing for better heat dissipation) and an AR stock adapter that has a very nice height adjustment system - which, unfortunately, I did not photograph very well.
Vltor's HK416 handguard - the exact designation of which I am unsure - is one of my favorite products, though I'm not really sold on the 416. I found it intriguing that the HK416 emitted a low, pulsating hum and fluoresces under UV light - no, just kidding.
You will soon be able to buy an AR that's almost entirely Vltor, as they've started manufacturing AR-15 lower receiver assemblies (they'll be sold as you see here for $379 starting in a few weeks). The three stand-out features are an enhanced magwell, an enlarged magazine release button, and a receiver endplate with side QD sockets that are tucked in close to the receiver.
Hopefully, in a month or so, I'll be able to report on some other Vltor news.
It's hard to find a more contentious topic in the AR world than "piston vs. DI" - that's why it's nice to have some hard data to work with.
Vltor conducted testing of 10.5" and 14.5" HK416s, specifically, their rates of fire, both suppressed and unsuppressed - incredibly, the 416's rate of fire with the stock buffer was as high as 1106 rounds per minute suppressed (10.5"), and 941 rounds per minute unsuppressed (14.5"). That's incredibly fast, and can cause a host of issues - among other things, many magazines just won't be able to keep up with such a high rate of fire. It's also harder to control a weapon that cycles at that speed, either on full auto or semi auto.
For comparison purposes, a Colt M4 is designed to shoot 800 rounds per minute unsuppressed.
With the Vltor A5 stock system and its extra heavy buffers, however (5.3oz stock, 6.1oz A5H3 and 6.9oz A5H4), rates of fire decreased to more manageable levels - 788 unsuppressed, and 914 suppressed (with the A5H4). That's a decrease of 187RPM for the suppressed setup. That's an incredible drop, and will increase the service life of certain components while making the weapon easier to shoot. Interestingly enough, the HK416's rate of fire (with the standard, non-A5 buffer system) is almost identical to some LWRC data that was recently posted on M4Carbine.net. Some other piston ARs have similarly fast cycling times.
If you want to know a little more about the A5, check out the video I made a few days ago -