Rodo,
Its not just an accuracy issue. Its a reliability issue, a parts issue, a weight issue, an an accuracy issue. The 416 was an example of one of the better piston guns, that still has it's weaknesses. The MAIN reason they are popular is for suppressor use. That is why they were designed.... beacuse guys who run nothing but cans (like DEVGRU) on 10.5 and 14.5 uppers wanted something that would run more reliable and work in a martitime enviroment. Guys like Larry Vickers who helped develop the 416 (and other HK rigs like the HK45 along with Hackthorn) will be the first to tell you, a piston gun is inferior outside of a small niche'. You also have to realize that it was developed durring a time when the Short Barreled AR was still an experiment. SEALS like the 416 beacuse it works good around water, and runs well supressed.
Since then, they have figured out port size, dwell times, and other variables to keep a 10.3"+ barrel running reliably both suppressed and unsuppresed. Here is an Article from HK's website that Vickers wrote.
http://www.hk-usa.com/-images/shared/HK M27 IAR.pdf. Even he says, unless you are running supressed, short barreled and/or very high round count in full auto, then a DI is a better choice.
You will also notice that Larry along with a bunch of other former SOCOM guys who instruct now, are not running 416 or piston guns as their primary rifles. Why do you think that is?
Lasty, to consider POF or LWRC as anywhere near the quality as a 416 (which has its own flaws that have been addressed on the accsesory market) is a joke. Also, a MR556 and a HK416 are not even close to the same gun.
Look at the high end AR industry, the trainers, the operators, the high vollume competetors................Ask yourself why guys are running DD, BCM and KAC SBR's when they could afford anything in the market. ALL DI guns.
This. And what "piston" guns is Chris Costa using, or putting his name on again?
I helped source some of the furniture for the original H&K M4 program for a guy who has already been mentioned here who was working for H&K at the time, and have followed its development into the 416, 417, and MR556, to include use of the carbines in my courses.
Guess what Larry uses in his courses? Well-built DI AR15's.
Guess what Kyle uses in his courses? Well-built DI AR15's.
Guess what Travis Haley uses in his courses? Well-built DI AR15's.
Guess what the guys who developed the Masada use in Magpul's courses (the company that said the AR15 needs the front sight pulled off and everything else replaced)? Well-built DI AR15's. Have you looked at the abortion that the Masada/ACR is? Bushmaster/Remington got sold a bill of goods on that deal.
So we have not only some of the world's most renowned high volume firearms trainers using well-built DI AR15's in their courses as the industry staple, but we have some of the most prominent figures who have designed op-rod driven guns, that they don't use in their own courses, yet I'm supposed to go out and buy one, or somehow believe this is the gold standard for reliability and accuracy, and that my DI guns are crap that will malf in a Chris Costa class?
I get to see how guns perform in the most extreme conditions, namely arctic, as in arctic, not cold, but in the arctic circle. High volume courses in the arctic with intermittent lulls are probably the harshest conditions you can run a weapon in, and guess what? Well-built AR15's/M4's are the gun to beat in my experience, unless you throw in the Finnish Valmet and Sako Rk series, which are an anomaly in the AK variant world, with magazines and brass-cased ammunition being critical components in their world-class reliability standard.
I've used almost every op-rod driven service rifle and assault rifle you can think of, minus the Indian and Indonesian guns, and whenever I hear someone claim that you don't need to clean these types of weapons, or they "run cleaner", a civilian mentality towards weapons maintenance is on display at that point.
Try telling your freaking team leader that you don't need to clean your gas block on the SAW or FAL, and in my day, you would literally get a well-deserved boot to the teeth. Spend time with your 1920's technology op-rod driven rifle over a week in the woods, mountains, jungle, or arctic, and tell me how your neglect to clean the gas block worked out for you.
In contrast, leave a DI AR15 family weapon lubricated with thick oil in the BCG, a chromed bore and chamber, and you will be much better off. This piston craze is almost as bad as the AK reliability myth. Spend some times with these guns overnight, day after day in dirty conditions, and you will have a totally different perspective on weapon's maintenance and reliability.
If you were a 1st-term soldier or Marine with crappy logistics support, your anecdotal experience with worn extractor, ejector, and recoil springs in a unit that was fanatic about white glove inspections has no real merit, unless you were arguing that there is a systemic leadership failure when it comes to having even the least degree of competency about weapons in general.
