Mid Length Gas System

[ssorg]

I came across this info on the "internets":

"The mid-length system is approximately half way between the carbine and rifle length gas systems, while maintaining the same barrel length as a carbine weapon. It was created for various reasons, primarily to increase gas pressure in an attempt to increase reliability of the carbine weapon. The U.S. military M193 and M855 spec ammunition does not generate enough pressure to cycle the carbine length system with 100% reliability in certain adverse conditions (this has been solved with high pressure loads like Mk262). So, the gas system was lengthened slightly on a carbine length weapon to generate more pressure to ensure reliable cycling."

Gas pressure is decreased.... Correct?

[Blob]

Yes, gas pressure is decreased with the midlength which helps prevent excessive wear and eases extraction.

Where did you find that?

[Robb Jensen]

Midlength cures very fast cyclic rates, less gas pressure at the gas port with less port erosion, heavy duty extractor spring are needed. Heavier buffers aren't required but many still run H buffers with them.

[bkb0000]

no... someone's seriously making shit up as he goes.

the idea behind the mid length is to reduce pressure, not increase it. and NATO ammo is hot, not weak.

[RogerinTPA]

I came across this info on the "internets":

"The mid-length system is approximately half way between the carbine and rifle length gas systems, while maintaining the same barrel length as a carbine weapon. It was created for various reasons, primarily to increase gas pressure in an attempt to increase reliability of the carbine weapon. The U.S. military M193 and M855 spec ammunition does not generate enough pressure to cycle the carbine length system with 100% reliability in certain adverse conditions (this has been solved with high pressure loads like Mk262). So, the gas system was lengthened slightly on a carbine length weapon to generate more pressure to ensure reliable cycling."

Gas pressure is decreased.... Correct?

Carbine, to Mid-length, to Rifle length, correct, decrease , not increase, in gas pressure. The further out the gas port is on the barrel, the less pressure. Rifle being optimum, as designed. Middy's solves the problems associated with the carbine. Where did you get that quote? TOS?

[ssorg]

http://forums.second-amendment.org/index.php?topic=753.0

A fairly detailed guide to have such misinformation I think

[ssorg]

http://www.youtube.com/watch?v=LKTH6f1JfX8

[Thomas M-4]

Either he miss wrote his post or he cant understand the graph he posted.

Just did a quick look over Nato ammo is loaded to higher pressure than .223.
LMT "Boutique" Brands WTF :rolleyes:
Big name brands
Rock River Arms
* Bushmaster
* Armalite
* DPMS
* Colt
other than colt all the others use shortcuts in manufacturing there arms IE they are cheaper.

This is the funniest :p Better still are receivers machined out of solid billet aluminum or steel. Solid steel :eek::rolleyes: only thing to be gained is weight.

[bkb0000]

Either he miss wrote his post or he cant understand the graph he posted.

no shit.. i'm guessing the graph was added without understanding what it means. unless he seriously typeod "reduced" and "increased" like 5 times... doubtful.

[RogerinTPA]

Either he miss wrote his post or he cant understand the graph he posted.

Sounds liked it. The graph is pretty self explanatory.

[ForTehNguyen]

carbines run 26k psi
midlengths run 19k psi
rifles run 13k psi

the midlength was originally created as a response to carbine problems which was found out to be the gas tube length. They moved the gas port up 2 inches without changing the barrel length

[bkb0000]

http://forums.second-amendment.org/index.php?topic=753.0

A fairly detailed guide to have such misinformation I think

Recoil has about as good an understanding of ARs and how they work as my 92 year old grandmother.

that whole website is a joke. it's the exact opposite of m4carbine.net- facts are laughed at, and the best answer to any given question is "DPMS"

[ssorg]

Midlength cures very fast cyclic rates, less gas pressure at the gas port with less port erosion, heavy duty extractor spring are needed. Heavier buffers aren't required but many still run H buffers with them.

Could you please elaborate on why you mention that a heavy duty extractor spring is needed for a middy? I'm building a middy and will have a BCM full auto bcg with the heavy duty spring/insert and crane o-ring. Is this more of a requirement for the middy? Is this a typo? Wouldn't the strong extractor and o-ring benefit ALL gas systems? I'm trying to understand this area better..

[Robb Jensen]

Could you please elaborate on why you mention that a heavy duty extractor spring is needed for a middy? I'm building a middy and will have a BCM full auto bcg with the heavy duty spring/insert and crane o-ring. Is this more of a requirement for the middy? Is this a typo? Wouldn't the strong extractor and o-ring benefit ALL gas systems? I'm trying to understand this area better..

It was a typo meant to be aren't needed.

I only use o-rings on CAR gas systems. I've seen so many cause feed problems among other things in larger gas systems because the guns owner 'overfixed' a CAR problem on a midlength.

[QuietShootr]

God, it's like someone distilled all the stupid from TOS, Glocktalk, and THR into one place, and sweetened it with a touch of keltecforums.


Recoil
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Re: LMT Releasing a .308 MRP
« Reply #1 on: November 15, 2009, 01:03:16 PM »
$3,000 for a rifle that doesn't shoot any better than a $1,100 DPMS, and locks you in to a proprietary barrel system, ensuring that for the rest of your life you have to buy overpriced barrels from LMT.

It's nothing but yet another rich man's gun.

[ssorg]

Thanks for the clarification - I'll remove the o-ring and start with that configuration.

[ssorg]

God, it's like someone distilled all the stupid from TOS, Glocktalk, and THR into one place, and sweetened it with a touch of keltecforums.

What is "TOS" ??

[cpekz]

What is "TOS" ??

ar15.com aka Arfcom

[ForTehNguyen]

What is "TOS" ??

"The Other Site" aka AR15.com