This is the article on the HK 416 with a 10.3" barrel. Click the READ MORE below to read the web article and find the video link.
HK 416
by Jessie Indracusin
Introduction
For any of my loyal viewers who read my articles and watch my videos, you are more than aware of my fascination with Heckler and Koch Firearms. Known for a level of accuracy, reliability and superior craftsmanship they go unmatched in the industry. I get a lot of people 
asking about what is the best AR to get. My answer to this question is one I do not give truthfully that much to people. The reason being is, if I suggest to most people to spend $4500-$5000 on a carbine, this is beyond most people's price range and interest in buying a rifle. There is, hands down, no AR platform rifle better than an HK 416. This does come down to the downsides of HKs…price.
Design
The HK 416 is a piston driven AR Platform. It accepts all standard AR/M4 magazines on the market. The barrels are all 1 in 7 twists so you can run hot loads (heavier grain bullets) in the gun. This holds true with a true 100% HK 416 and the one being reviewed here. So let me explain this a bit. As a civilian, this is the only realistic option of getting an HK 416. Heckler and Koch does not sell these directly to the public. They are INCREDIBLY difficult to get, you have to wait forever, deal with a lot of liars along the way (as far as having one to sell or getting one) and you need to get an SBR Tax stamp. The HK 416 came traditional in 2 barrel lengths, the 10.3" barrel, being reviewed here, and the 14.5" barrel. Both barrels are less than 16", so you need a stamp. Since there was no such thing as a semi-auto HK 416, your only option is to really buy a HK 416 upper (which by itself you are LUCKY to get one under $4000). Expect to pay a HUGE premium for spare parts, etc. because of the rarity of this gun. This is not something to casually decide to get. Please note, I can NOT provide any guidance on helping you find an HK 416 upper or parts for this gun. This truly is an easter egg hunt type purchase. You have to be truly dedicated to spending a lot of disposable income to go down this line. If you are a law enforcement department (not just an active officer, since the weapon can only be sold directly to the 
department) and have the funds, you can buy one of these for about $3500 a unit from HK (or less). If I was a Chief of Police, I would send my officers to find a drug dealer and beat him to a bloody pulp, take the money and use it to procure these rifles (okay, I am joking and am not advicating violence against a person who has not had due process since I do have a law enforcement background in a past career).
The HK 416 is solid. When I mean solid, I mean in every way. You could probably drive over this rifle with a tank, pick it up and shoot it flawlessly. If you ever have a chance of looking at one of these upclose, you will know that HK has not spared a cent on making the highest quality rifle. You could probably dunk this gun in salt water for 48 hours and shoot it without incident. The gun definitely feels a bit heavier, the barrel is DEFINITELY heavier, than a typical rifle.
Testing/Setup
The platform we are using for the article is a Colt 6920 lower. When you get an HK 416 upper you need to register the gun as an SBR (Short Barrel Rifle) because of the two most common (and pretty much the ONLY barrels you can find) lengths of the barrel, 14.5 and 10.3 inches. When you register this upper, you have to register it to the model and serial number of the lower. YOU CAN NOT LEGALLY PUT THE UPPER ON ANY OTHER LOWER AFTER YOU GET YOUR PAPERWORK! You will need to carefully choose the lower you want, so PLEASE do not buy some cheap Bushmaster lower after spending this type of money on an upper. You want to get a solid lower. We utilized a Larue vertical fore grip and an Aimpoint T-1 for testing. During the testing, we used Blackhills ammunition at 55 grain and also fired some cheap reload ammunition. Testing used various AR mags. During the testing, we have NOT been able to figure out any way of making 
this gun jam. Slow fire, rapid fire, junk ammo, etc. the gun can just run. We did not run any higher grain loads through it, but do not anticipate any issues.
Conclusions
Within the next few weeks, you will see the upcoming range time video on this. I will talk more about the performance of this gun during the segment (even shooting with a short 10.3" barrel). Bottom line, if you can float the bill, find it and want to spend the time to invest in the paperwork, etc., this is an excellent option.
Design: 
Reliability:
Accuracy:
Cost:
Overall: