M-4
Car-15
Mid-Length
Recon
Recce

I need help trying to find out which one of these is 16-inch with out a Flash hider or Muzzle break.  And Also just for my own ettification what are the differences of these rifles.  Thanks is advance.  (Ar's are starting to get adicting and I dont have one yet)

Hound/Scott

i'm no expert but i'll try since no one else has answered.
M4: COLT brand 14.5" bbl, oversize feeding ramps.
CAR-15: any mid-length collapsable AR
Mid-Length: 14.5" to 16" bbl.
recon/recce: same thing, any CAR-15 with options for accessories for forward deployed reconnaissance units.
this is my meager understanding of the definitions you needed. if i am wrong, i'm absolutely certain someone will point it out as that is kind of a sport here.

if you want a 16" barrel without threads, a simple call to bushmaster will get one to your doorstep. you can also visit bushmaster.com and order one from there. also, if your going to order one, pony up the extra 30 bucks or whatever and get it fluted, you'll be happy you did. i hope i helped some.  

Quoted: i'm no expert but i'll try since no one else has answered. M4: COLT brand 14.5" bbl, enlongated  feeding ramps. CAR-15: any mid-length collapsable AR Mid-Length: Longer hand guard than carbine, short than standard. recon/recce: same thing, any CAR-15 with options for accessories for forward deployed reconnaissance units. this is my meager understanding of the definitions you needed. if i am wrong, i'm absolutely certain someone will point it out as that is kind of a sport here. if you want a 16" barrel without threads, a simple call to bushmaster will get one to your doorstep. you can also visit bushmaster.com and order one from there. also, if your going to order one, pony up the extra 30 bucks or whatever and get it fluted, you'll be happy you did. i hope i helped some.

M4 - Carbine length gas system, barrel cut for mounting M203 grenade launcher and upper rec. and barrel extention are cut for a lower and wider feed ramp.

Car-15 - Carbine length gas system, light profile barrel.

Midlength - Any AR with a midlength gas system.

Recce/Recon - Carbine length gas system, FF rail, magnified optic (ACOG, Short dot, Accupoint, etc...)  There are many threads on these if you do a search.  I believe this was a SEAL request for a M4 with a bit more reach for counter sniper type work, but that would still work for CQB.  What they got was the SPR.  

Any of these may have a 16" barrel.  -Ian