What is a middie?
Middie = Mid-Length gas system
Carbine
Mid
Rifle
The military won’t switch, it shouldn’t. A few modifications to the current system would be the most cost-effective solution. A new round would probably be best. But, as everyone else is saying, the reasoning to switch isn’t there. Nothing has come out that completely destroys the DI M4. Switching would not only cost a HUGE amount, but then you have to retrain EVERYONE on the system. And, the AR piston system has not been refined for 40+ years with fielding in just about every situation and application possible.
I’m sorry but I’m still confused as the M4 barrel has it’s gas port at 7.5 inches of a 14.5 inch barrel, doesn’t that make it a “middie?”
yes and no, in a 14.5" barrel with 7" gas port makes it equivalent to a 16" barrel and a 9" gas port. for all practical purposes here though most people have a 16" barrel and a 7" gas port (most typical civilian carbine configuration). Most can’t get anything less than a 16" barrel due to legal restrictions (NFA). Personally I wouldn’t want a barrel with a flash hider welded on.
No. A mid-length gas system is hallmarked by the length of the gas tube, in and of itself, not where it falls on the length of any given barrel.
Carbine = 7" gas tube
Mid-length = 9" gas tube
Rifle = whatever length a rifle gas tube is. 11", innit?
The mid-length gas port is 9.5 inches from the chamber. Rifles in this configuration are what is being referred to when you hear “mid-length” or “middy/middie”.
ETA: Rifle is 13 inches, not 11.
but you can have the equivalent by dropping the barrel length to 14.5" and a 7" gas tube.
No, not “yes and no.” Just “No.”
A 16" w/mid-length gas is a 16" w/mid-length gas.
It is not “equivalent” to a 14.5" barrel w/carbine gas, because you have two dimensions that are completely dissimilar from one another. Add the variables like ammo, buffer, spring, wear rates of all and other components…
“Equivalent” according to which metric?
And, what’s this got to do with what the military supposedly is or is not going to select or how it supposedly (which is to say, largely imaginarily…) views mid-length gas systems?
Thanks guys, makes sense now, found this too.
http://www.03designgroup.com/technotes/carbine-vs-mid-length-gas-system
keep in mind those are with 16" barrels…
equivalent as in the gas pressure and dwell time. Todd asked a specific question about middies thus the branching off. sorry i didn’t know we cud not deviate from topic … like at all…:rolleyes:
Ok, just lay it out for me, when the OP refers to the military going to a middie what does he mean?
right now the mil only uses carbines and rifle lengths. the middie is a relative newcomer to the market and is basically in the civilian sector right now. my question was does do people think the mil will eventually adopt the middie or not.
What is it, length, specs, etc.???
It’s not that you’re deviating from the topic. It’s that you’re completely wrong.
Both the port pressure and the dwell would be different in those two set ups.
You’re posting on a board where people actually know shit… not AR15.com. And it’s abundantly clear that you don’t know what you’re talking about… and don’t even know it.
help me understand because i read that if you have a 16" barrel and a 9" gas tube that you could create the same performance by going to a 14.5" barrel and a 7" gas tube. it makes sense that cutting off 2" off the barrel would give you the same dwell time. where’s my disconnect? 
wow lol … ur kind of a jerk about it huh? sheesh sorry master of the universe…
M4C can be harsh sometimes. The carbine and middies are not going to act the same because the pressures are going to be different. The pressure 7 inches down the barrel is going to be different that at 9 inches no matter where the port and muzzle are.
in your opinion would you rather have a carbine (that is 16" barrel and 7" gas tube) or a middie (that is 16" barrel and 9" gas tube)?