gas port

[colek50]

bros, does the gas port location of the pistol type barrel for m4 differ from the location or distance of the gas port of the carbine type barrel for m4? both having 11.5 inches in barrel lenght... the carbine type and pistol type

[Col_Crocs]

Taken off your last thread... You may have missed it.


It should be exactly the same.

The only difference between a carbine and a pistol is the pistol upper has to be mated on a lower receiver designate as a pistol lower at its time of manufacture (which I think is what the poster above was trying to say.

The gas port, and everything else, should be the same between the two.

[Col_Crocs]

AR15 pistol, registered SBR or MG are classifications under which one is allowed to legally own a barrel shorter than 16.1 inches, +- a few other features and technicalities which I am not qualified to further discuss.

Gas port location has to do with "gas system" and not it's classification as a complete weapon. That said, 11.5's only come in a carbine gas system which has its gas port 7inches down the barrel. The exact same location as that on a 10.3, 10.5, 11.5, 12.5, or carbine 14.5 and carbine 16.1. These said lengths, however, differ in gas port size for them to function properly.

[colek50]

thank you very much... i

m just confused... because i was told in another forum, (ar15.com) by a fellow member there that pistol type barrel and carbine type barrel differs in the location of the port... the carbine type located 7 inches down the barrel... and the pistol type much lower...

and here i was told that is should be with the same location...

( both barrels having 11.5 inches...saw them at m1sales)

[thopkins22]

i was told in another forum, (ar15.com)[/B] by a fellow member there that pistol type barrel and carbine type barrel differs in the location of the port... the carbine type located 7 inches down the barrel... and the pistol type much lower...

and here i was told that is should be with the same location...

These are clues.;)

My guess is that model one is interested in making their primary customer base that probably doesn't really understand the platform nor the laws regarding pistols and SBRs to feel comfortable putting rifle parts on a "pistol."

[Col_Crocs]

These are clues.;)

My guess is that model one is interested in making their primary customer base that probably doesn't really understand the platform nor the laws regarding pistols and SBRs to feel comfortable putting rifle parts on a "pistol."

Yup! Took a stab at their site and saw the same barrel posted in different categories/classifications: Pistol and Commando (SBR).
here's how it was labeled in the pistol cat:
"11 1/2'' Pistol Chrome Moly Barrel, 1-9 twist, threaded muzzle
In accordance with federal firearm laws, Pistol Kits are for use only with lower receivers originally manufactured and recorded as pistol receivers. Do not use with 'Rifle' receivers!"
and the Commando (SBR) cat:
"FOR FULL AUTO or REGISTERED SHORT BARREL RIFLES - NFA RULES APPLY!"
No offense to the guys running it but the site is in need of some major re-categorization and re-organization IMHO. :confused:

[colek50]

so bros, is it in the same location? the gas port of pistol type and carbine type? thanks again

[Robb Jensen]

Gas system lengths:

Pistol (for very short barrels, less than 10.5"s)
CAR (Colt design for 10.5"-14.5" and on the civilian side 16" barrels)
Midlength (ArmaLite design but used by most others, for 14.5"-18" barrels).
Midlength (KAC design a little longer than ArmaLites, used on 16" barrels)
Intermediate (VLTOR design, designed specificially for 18" barrels)
Rifle (Colt design, designed for 20"-24" barrels, does work pretty well with 20" barrels cut down to 18")

If your barrel is a common CAR length gas system then no there is no difference with your barrel and a common 10.5" rifle barrel. If your 10.5" is a .300 Whisper for example then it very likely has a pistol length gas system.

[hellbound]

wasn't this same thread posted a couple days ago?

you're other answer came from TOS, which is what we call a clue. the tech forums over there are garbage. it's a bunch of new guys parroting the same stupid answers that some other new guy told them when they first joined, 90% of the time those answers are wrong. but don't tell them otherwise or you are a troll.

there's a reason, guys like QUIB and other assets to the tech forums no longer posts there.

[Col_Crocs]

so bros, is it in the same location? the gas port of pistol type and carbine type? thanks again

My goodness...:rolleyes:
Again, there is no difference in locations with the 11.5" barrels in question.
For other lengths, refer to GotM4s post.

[colek50]

col crocs. . . somebody at ar15.com told me this...

Pistol 4.7" gas port location - 7" to 11.5" barrel lenght

Carbine 7.8" gas port location - 11.5" up to 16" barrel lenght

both having 11.5 inches... gas port will be different because pistol type is 4,7 inch away and carbine type 7 inches away...

sorry for repeating this question... im just trying to make sure what really is true...

thank you for your understanding...

[thopkins22]

You make my head hurt. Since you're looking at M1 go here. http://www.model1sales.com/item-detail.cfm?ID=BPI150&storeid=1&image=barpistol.gif&CFID=61904614&CFTOKEN=15794059

At the top of the page there are pictures of the respective "pistol" barrels. Only one of them has a pistol length gas system(the top one.) You'll notice that it's a 7.5" barrel.

Model 1 is calling the regular damned carbine length gas system short barrels "pistol barrels" for the reasons I explained earlier. The 11.5 barrel that comes up in their "pistol" menu is assuredly the same barrel that comes up under "commando."

[Robb Jensen]

To the OP gas system length has direct relationship to length of the barrel (and caliber) vs. if the upper is actually on a pistol, rifle, SBR or machinegun.

You could build a RIFLE with a 40" .300 Whisper barrel and it will still have PISTOL length gas system. (an old co-worker did just this)

You could build a PISTOL with a 20" 5.56mm barrel with a RIFLE gas system.

For 11.5" barrels in 5.56mm RIFLE or PISTOL both will have CARBINE length gas systems.


In case you missed it before:

Gas system lengths:

Pistol (for very short barrels, less than 10.5"s)
CAR (Colt design for 10.5"-14.5" and on the civilian side 16" barrels)
Midlength (ArmaLite design but used by most others, for 14.5"-18" barrels).
Midlength (KAC design a little longer than ArmaLites, used on 16" barrels)
Intermediate (VLTOR design, designed specificially for 18" barrels)
Rifle (Colt design, designed for 20"-24" barrels, does work pretty well with 20" barrels cut down to 18")

[colek50]

thank you very much for explanation.... esp with the pic of m1sales... bro gotm4...

thank you for your patience...

now i fully understand... i forwarded alll your explanations to my friend ...

thank you very much bros...

[colek50]

bro thopskin22 ... thank you very much ...