AR Carbine VS Mid Length

[pennys dad]

Hi Everyone

My friend found this write up on AR Carbine vs Mid Length. I am fairly new to the current AR scene and this is an old writeup, does it still have value as good information or did it have value when it was first written?

Thx for the help

http://www.thehighroad.org/showthread.php?t=199626

[dieselpower]

Its technicaly correct. But the failures it deals with are only for full auto, even bump-firing an AR is not as fast as true full auto, since the trigger still needs to be reset. In any event a H-buffer fixes any other problems by slowing the bolt down with more resistance then a standard buffer.

[aplinker]

Its technicaly correct. But the failures it deals with are only for full auto, even bump-firing an AR is not as fast as true full auto, since the trigger still needs to be reset. In any event a H-buffer fixes any other problems by slowing the bolt down with more resistance then a standard buffer.

What are you talking about? The discussion has nothing to do with FA.

[dieselpower]

well no, but then again yes

What are you talking about? The discussion has nothing to do with FA.

You are right the OP was not about FA, but about the write-up. In which case the author wrote the whole thing to summarize his view that the M4s gas system was unstable.

Even in the last paragraph he gave examples of how to "fix' the problem with pigtail gas tubes. But there is no real problem with the M4s gas system when the weapon is properly configured. Further more these "problems" only crop up sporadically on full auto M4s that are not configured properly.

[bobfried]

What are you talking about? The discussion has nothing to do with FA.

What he said.

The entire thread dealt with a single round, heck it could have been talking about a single shot self extractor. Whatever the case, it has been stated and remains true to this day that reliability is like this:

Carbine < Mid-Length < Rifle

So when you can have a rifle length gas system you get that, if you HAD to you'd go to a Mid-Length, than if the length won't allow it you go to a carbine gas system. Than if your really really crazy and want a super shorty than you have to go to the abbreviated gas system. Nowhere does it say that if you CAN have a longer gas system should you go for the shorter.

[aplinker]

You are right the OP was not about FA, but about the write-up. In which case the author wrote the whole thing to summarize his view that the M4s gas system was unstable.

Even in the last paragraph he gave examples of how to "fix' the problem with pigtail gas tubes. But there is no real problem with the M4s gas system when the weapon is properly configured. Further more these "problems" only crop up sporadically on full auto M4s that are not configured properly.

Not trying to be mean, but you don't know what you're talking about.

There are significant problems with a carbine gassed rifle. There are "fixes" that help to reduce the issues, but the bottom line is the design is inherently flawed. This is why there's a massive migration to mid-length gas systems, especially for 16" rifles.

[dieselpower]

I understand what you are saying, and do agree to a point. IMHO the M16 and M4 platforms are two different creatures, each with their own flaws.

You can not simply cut down a 20" and expect it to work. The government was told this when they first asked for the carbine. The answer was to just do it using the best math they could and adjust from there.

It has been found that the "problems" start to become noticeable at FA speeds. Yes the actual problem is there from the start, but its not any more of a hindrance to the shooter then the hindrances you are trying to aviod by having a carbine with a shorter barrel.

So a 16" carbine properly configured in semi-auto is just as reliable as a 20" or 18". Is it 100% the same in those terms, "No". Its a "Monk" issue. Its like saying a bat has the ability to hear the crappy sound coming from my $2000 audio system so its not good enough for me.

The problem only becomes a problem when you are running FA, then you really need to start fixing it.

Just like most here, I have been firing semi-auto in 16" carbine ARs for over a decade, and before that I was firing select fire burst and full auto in the military. Of all the things to worry about in the AR15 platform, this is the last.

Is the author technically correct with all the math, "hell yes". Is he making a mountain out of a mole hill, "hell yes". Will this mole hill get bigger at FA speeds, "hell yes".

You can take 100 semi-auto middys and 100 16" carbines to the range and of all the things to go wrong with BOTH groups, failures due to the gas system will = next to nothing. Its not worth the cost of the calcuator to figure it out.

If you get right down to it, the AR15 (any length gas system) is a POS when compared to other weapons of higher quality. But we are willing to let that slide due to all the benefits it has. No weapon is perfect.

As far as everyone moving to middy length, thats fine. What happens when someone finds out adding 1/8 of an inch to that length increases accuracy or reliability? Is the middy now a POS and can't be trusted to shoot with?

At some point you have to tell "monk" to stop, its ok as it is.

Once again, I do agree, the math and technical stuff do add up to a problem with the M4s gas system.

[aplinker]

Sorry, but you're 100% wrong, not to mention your arguments are entirely hand-waving and babbling.

The failure rate of bolts in M4's is in the 60-70% range. The failure rate with the M16 is almost nil.

This is because of the gas issues caused by the carbine overpressure.

Is that to say all of them will suck right off the bat? No. The fact of the matter is that there is a significantly higher failure rate due to the stresses of the carbine gas system with a 14.5" barrel - this gets even worse with a 16" barrel (or longer), due to the increased dwell time.

I understand what you are saying, and do agree to a point. IMHO the M16 and M4 platforms are two different creatures, each with their own flaws.

You can not simply cut down a 20" and expect it to work. The government was told this when they first asked for the carbine. The answer was to just do it using the best math they could and adjust from there.

It has been found that the "problems" start to become noticeable at FA speeds. Yes the actual problem is there from the start, but its not any more of a hindrance to the shooter then the hindrances you are trying to aviod by having a carbine with a shorter barrel.

So a 16" carbine properly configured in semi-auto is just as reliable as a 20" or 18". Is it 100% the same in those terms, "No". Its a "Monk" issue. Its like saying a bat has the ability to hear the crappy sound coming from my $2000 audio system so its not good enough for me.

The problem only becomes a problem when you are running FA, then you really need to start fixing it.

Just like most here, I have been firing semi-auto in 16" carbine ARs for over a decade, and before that I was firing select fire burst and full auto in the military. Of all the things to worry about in the AR15 platform, this is the last.

Is the author technically correct with all the math, "hell yes". Is he making a mountain out of a mole hill, "hell yes". Will this mole hill get bigger at FA speeds, "hell yes".

You can take 100 semi-auto middys and 100 16" carbines to the range and of all the things to go wrong with BOTH groups, failures due to the gas system will = next to nothing. Its not worth the cost of the calcuator to figure it out.

If you get right down to it, the AR15 (any length gas system) is a POS when compared to other weapons of higher quality. But we are willing to let that slide due to all the benefits it has. No weapon is perfect.

As far as everyone moving to middy length, thats fine. What happens when someone finds out adding 1/8 of an inch to that length increases accuracy or reliability? Is the middy now a POS and can't be trusted to shoot with?

At some point you have to tell "monk" to stop, its ok as it is.

Once again, I do agree, the math and technical stuff do add up to a problem with the M4s gas system.

[dieselpower]

fine.

Sorry, but you're 100% wrong, not to mention your arguments are entirely hand-waving and babbling.

The failure rate of bolts in M4's is in the 60-70% range. The failure rate with the M16 is almost nil.

This is because of the gas issues caused by the carbine overpressure.

Is that to say all of them will suck right off the bat? No. The fact of the matter is that there is a significantly higher failure rate due to the stresses of the carbine gas system with a 14.5" barrel - this gets even worse with a 16" barrel (or longer), due to the increased dwell time.

Fine, I will agree 60% - 70% of all the US Armys M4s fail in firefights.

I guess my unit was just lucky.

you win.

[slappomatt]

lol. MIDLENGHT FTW. thats all there is to it. carbine sucks.

[ar15barrels]

https://www.ar15barrels.com/prod/operation.shtml

[Adonlude]

lol. MIDLENGHT FTW. thats all there is to it. carbine sucks.

Darn it. Wish I hadn't wasted so much money. Guess I better throw my Noveske N4 away. It will be in the trash outside my house if anyone wants to use it for scrap.

[B Strong]

I went through the Front Sight tactical carbine class four years ago, and one of the students had a bolt failure in his Colt M4rgy on the second day.

I was using a carbine length Bushmaster with a 16" barrel, pigtail gas tube and the H buffer, and other users commented on how much "smoother" my rifle ran v. theirs.

The problems discussed in the FL article are true to my knowledge.

[ar15barrels]

Just like most here, I have been firing semi-auto in 16" carbine ARs for over a decade,

If you get right down to it, the AR15 (any length gas system) is a POS when compared to other weapons of higher quality.

First off, most here have NOT been firing semi-auto 16" carbines for over a decade.

What are these higher quality weapons you speak of?

[River Jack]

So does this mean that a 14.5" barrel has a significantly higher potential to have failure issues than a 16" or an 18"?