In all honesty, who knows guns well enough, and is paying close enough attention (And maybe even freeze framing) to notice this? Maybe 1 out of 100 or 1000 viewers or less? It's not a Big Budget movie, it's a low budget TNT TV Series, they have to make do with what they have, maybe they got the weapons in a big bulk deal? I'm sure the budget gets pretty chewed up by the Skitters, the Mechs, The Skinnies, the Space Ships, probably not much left of the budget after those effects and paying the Actors and crew.
You're right, very few viewers are going to notice or care about such issues. As a soldier who has handled such weapons I am far more attuned to that stuff than the average person.
But here is what bothers me. It would not take any increase in budget to swap out the DShK for an M2(they already have at least one M2 on set), changing the line likewise requires no increase in budget. All it requires is for the writers to do a little research(five minutes on Wiki would suffice) and not be lazy. If the sometimes goofy lighthearted Stargate shows could get things generally right(in terms of firearms), then certainly Falling Skies should be able to.
I don't mind a visual modification of calling a 12.7mm gun a 20mm. What gets me is how "sabot" has become the magic word. With no onscreen nod to how the high kinetic energy coming out of the barrel is what makes sabot rounds work. I first noticed in the first Transformers where the Special Forces where shooting "sabot" rounds from low powered grenade launchers and that was the only thing which would slow a robot down.
In Falling Skies, 50 cal or 20mm with discarding sabot would break their "technical" gun cars apart. And I see the 2nd Mass still has weapons from every nation on earth special forces units
Yeah, the magical sabot rounds are always good for a laugh. Sabot rounds are a little longer than normal rounds, and are fired at a higher velocity. They are not going to work with a low velocity grenade launcher.
A 20mm might break the suspension of a technical, but I've seen DShKs and M2s mounted on pick-up trucks in Iraq, if the pintle mount is welded on well enough it works fine. 50 caliber SLAP(Saboted Light Armor Penetrator) ammunition is fired at a higher velocity than standard ball ammunition, but the round itself is lighter, meaning there is no real increase in recoil.
As to the small arms of the 2nd Mass they are too varied for my taste(keeping all those various sizes of rounds in stock would be a logistical nightmare, as well as different lubes and replacement parts). Just in the second season so far we have seen a Beretta 92FS, Colt Python, S&W 5906, Taurus 689, M4A1, IMI Galil, H&K G36K, H&K 91, M1 carbine, SIG 552, M1A, Beretta M12, H&K MP5. But our heroes could have run across such varied weapons without stretching believability too far. Most are either legal in the US(in civilian variants) or used by military, law enforcement or security groups in some capacity. Until Ben(5.56mm) and Hal(7.62mm) start trading magazines during a firefight or something, I am willing to give the show a pass on small arms.
But again, the gun issue is not going to determine if Falling Skies is a good show or a bad show. All it illustrates to me is that there is a lack of attention to detail somewhere on the production side, and the writers are either ignorant or too lazy to fix things. Or more probably they just think it makes our heroes look more ragtag and "cool" if everyone is using a different weapon.
.
Whatever. I guess nobody watches NFL Football any more, not to mention the other equally valid pre-Trek historical references.
