AR15 mid length vs shorter carbine

[TexasEd]

Is there a big differnce in the Mid length vs the shorter carbine on the M4 platform. Some say the reliabilty is better with the mid length system. I know RRA and Armalite and some others do the Mid length rifle.

 

[briansmithwins]

What question are you asking, exactly?

A 16" midlength has a smoother recoil impulse than a 16" carbine. Without going SBR or permattaching your flash hider you're stuck with the federal 16" minimum barrel length anyway. BSW

 

[cameron.personal]

briansmithwins the gas system length can be different regardless of barrel length. I think the that the mid-length gas system is a marginally better option on a 16" AR15, there are a lot of technical reasons, but it simply puts less stress on the system than the shorter carbine length.

I have both on two 16" ARs and if I had a choice I would opt for the the mid-length, however I wouldn't worry about a carbine length gas system either.

Both of mine have been 100% reliable and they feel just about the same to shoot.

Cameron

 

[longdayjake]

I have had much better results with my midlength than I have with my carbine. However they are two different brands and that may be the only difference worth considering.

 

[IndianaBoy]

My carbine has gobbled down thousands of rounds of brass cased milsurp and steel cased wolf... with nary a hiccup.

Don't worry about reliability. Buy a quality rifle and you will be fine. Avoid bargain basement parts.

 

[trigga]

so increasing the gas tube length would decrease stress during blow back, and increasing the buffer tube will reduce recoil result in more accurate shots?? sorry random question but makes sense. great combination.

 

[Bartholomew Roberts]

so increasing the gas tube length would decrease stress during blow back

Not entirely. The AR15 was originally designed as a 20" barrel with the gas port about 13" down the barrel and a port pressure of 15k psi.

That is what all of the internal parts were designed around as well. When you change the barrel length and location of the gas port, it can affect function. As you decrease barrel length, you increase port pressure. As a general rule, the closer you can get to the rifle length, the less the port pressure is and the more the time to operate is like the original design. However, you also need a certain amount of barrel length after the gas port or all the gas exits the muzzle before it can be diverted to the gas port in sufficient qualities - so too long of a gas system on a short barrel (10.5" barrel with carbine gas or a rifle length on a 16" barrel for example) can be a problem too.

and increasing the buffer tube will reduce recoil result in more accurate shots??

Increasing the buffer mass delays the time it takes for the rifle to unlock and can help correct a rifle that is getting too much gas by giving it a heavier mass to push against (this is why the M4 has the H-buffer). Shooters have also found that subjectively, it may make recoil feel smoother - or delay the recoil impulse across a longer period of time. Some shooters go the opposite route though and feel a lighter mass disturbs the sight picture less.

My own personal test is to put a timer on the rifle and see if I can notice a difference in my performance. I can "feel" a difference; but it doesn't translate into any practical time advantage to me, so I stick with what cycles the rifle reliably.

Like messing with the gas system, messing with the buffer is a good way to "enhance" your rifle right into unreliability if you don't know what you are doing.

 

[P.B.Walsh]

Can't you put a bayonet on a mid-length.

 

[Al Thompson]

You can put a bayonet on anything with enough duck tape.

 

[Gary G23]

"Can't you put a bayonet on a mid-length."

hell yeah

 

[bfoosh006]

Atta' boy, Gary !

 

[Dr. Tad Hussein Winslow]

Sidebar (sorry): Anyone make a "Middy Dissy"? I.e. A 16" rifle, with full-length handguard and fake gas block/handguard holder, with a mid-length gas system hidden under the FL handguards?

 

[Lucky Strike]

All the reliability issues aside (personally i think both are more then enough as long as it isn't a real shady brand) the midlength looks better in a 16" barrel IMO.

If you want a top notch quality midlength look at Bravo Company...i've got one of their midlengths and the quality is right up there with Colt and LMT

 

[sarduy]

flip a coin!

 

[Zach S]

Sidebar (sorry): Anyone make a "Middy Dissy"? I.e. A 16" rifle, with full-length handguard and fake gas block/handguard holder, with a mid-length gas system hidden under the FL handguards?

CMMG. And unless they've added any profile options, you can only get them with their MedCon profile, which is a cross between the GI and HBAR (IIRC mine is .840 from the chamber to the CAR FSB position). When I got mine, 1:7 was the only twist available.

Shortly after I got my upper, I shot someone's 18" AR. It was a 20" CMMG GI profile bbl that had been cut down by Randall before the arfcom mess. It balanced better than mine, and of course had a smoother recoil. Both rifles wore stock HGs and M4 stocks.

I plan on changing mine over to an 18" bbl, and having my 16" turned down by adco. Then I'll have an extra bbl, and a reason to build another rifle. But I'll build it for my wife, maybe then she'll stop referring to my 9mm as her AR.

 

[10-Ring]

My 223 is mid-length & 100% reliable. My 9mm is carbine length & 100% reliable. 223 has about 3k rounds through it & the 9mm almost 5k