Depends what you consider "retro"...

So, there's a running joke on Facebook where Caleb will post a picture of one of the issue M4's from work and I'll crack wise about the Air Force issuing "retro" guns.

Mind you, they're pretty standard M4's, it's just that the guns found out in the non-SOCOM parts of the armed forces are, by the standards of the current state-of-the-art, kinda old school. You know, the way guys in line units during OIF were clearing houses with Maglites hose-clamped to the handguards of their A2's while cake-eating civilian me here at home had a Surefire M500 on her ban-compliant house gun.

Some of his fellow airmen didn't get the joke, though. "Those aren't retro! Those are standard issue!" Yeah, so are birth control glasses...

David Merrill over at RECOIL is the sort of AR geek who can tell you pretty much when a rifle was put together with remarkable accuracy just by the configuration of gun and accessories.

I'm not that good, but I can get within a few years. I showed the below picture of my previous house gun (taken in Marko's driveway a couple years ago) to one of the Surefire reps at the class in Alliance last week and he said "Man, that looks like an EAG class gun from '08 or '09," and he was pretty spot on. That gun had been built at the end of 2012 and its configuration had been heavily influenced by Pat Rogers' articles in SWAT over the previous several years.

But hardware trends are definitely a thing. A lot of them start in 3 Gun competition shooting and percolate into the tactical world. An example of that would be low-power variable optics. Once magnifying scopes rugged enough to take a whack became a thing, it was only a matter of time before they became the choice of serious dudes.
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