16" AR15 barrel question

[pklin1297]

Hello all,

Trying to decide on the gas port position for the 16" barrel I will soon get, so I have the following questions:

16" with carbine length gas port vs. 16" with mid length gas port

What are some pros/cons between these two barrels? Don't know if it matters, but I have a M16 bolt carrier group, which I believe is heavier than a regular AR15group? Just wondering if either barrel coupled with a heavier bolt carrier group will have an adverse effect on the cycling and reliable function on my first AR.

Thanks much!

[etruscan]

i am by no means a master scholar of the AR so dont go to the bank with my two bits. theres a graph out there somewhere (ive seen it) that shows the different gas pressure curves for the different gas system lengths. carbine length systems have the most burtal curve with rifle length the most relaxed, and midlength right in the middle (duh). you really dont have to worry about reliability issues when you have in your possession a component designed to work with these gas pressures. as long as you keep you rifle clean and in proper running order, worries regarding reliability will be a very very very minimal issue. thats my experience at least. for me, the choice between carbine or midlength is mostly aesthetic (my ARs arent "working" rifles). but they do get a good workout.

[adamsreeftank]

The carbine length gas system was designed for the 14.5 inch M4 barrel. If you are using a 16" and have the option, I recommend you use a mid-length gas system. In addition to less wear and tear on the rifle, there is also less dwell time as the bullet passes the gas port and exits the barrel. Theoretically, this should improve accuracy as the bolt is less likely to start reciprocating before the bullet has exited the gun.

[bwiese]

For most civvy/sport/LEO shooters the CAR-style vs. "middy" gas systems will be irrelevant.

I used to be wholly against them given they were 'new', and not really field-tested in heavy use. But they've been around awhile so I think companies are pretty much up to speed on them and know about gas port sizes vs buffers, cycle times, etc.) Sometimes you wanna make sure a 'fix' for something doesn't introduce new problems, and that it's been adequately tested.

The middy gas systems require different nonstandard handguards, and a different gas tube. These are still a bit less common if you have problems so I'd recommend getting, at least, a spare middy gas tube or two to have on hand given that most commonly available gas tubes are rifle or CAR-15 length.

One place where a middy gas system can be really useful is in a 'Dissipator'-style rifle. These rifles have the iron sight radius of a rifle w/20" barrel (that is, front sight is same distance from rear sight as on a std M16A2 rifle) but the front sight block only serves as a sight and not a gas block. The gas block is separate from the front sight and is instead placed under the rifle handguards - it must be 'low profile' to fit under the handguard + heat shields.

The Dissipator is nice because, aside from the longer rifle-length sight radius, the handguards extend further and you won't fry your hand on a hot barrel

The Bushy Dissipator I have has a CAR15 position gas tap, but there is no reason why a middy gas tap system would not work or be implementable on a 16" Dissipator-style configuration.

[In fact, I believe such an option/configuration may indeed be offered by CMMG! They have some different terminology for their 16" middy build with a rifle-position front sight, and they may have some other barrel profile options - lightweight, midweight, HBar, bull.... ]

BTW, a 16" Dissipator-style AR with an A1 stock is pretty damned handy and not that much longer than a retracted CAR15. It's one of my favorite platforms - I think a few of you at the July Chabot Shoot-N-Q shot my Dissipator + Elcan and saw how good a gun it was.

[pklin1297]

Thanks guys for your help... This is all good information for me to consider...

Now for the barrel itself:

Where, besides Noveske and AR15barrels, can I get a well manufactured 16" barrel that will shoot accurately at the usual prescribed distances but not break the bank? I have looked into White Oak Armament and CMMG... I am planning to get a stainless steel barrel, not a chrome-moly and chrome-lined. Any thoughts?

Thank you.

[bwiese]

Where, besides Noveske and AR15barrels, can I get a well manufactured 16" barrel that will shoot accurately at the usual prescribed distances but not break the bank? I have looked into White Oak Armament and CMMG... I am planning to get a stainless steel barrel, not a chrome-moly and chrome-lined. Any thoughts?

Don't do this. Unless you're building a match rifle or spacegun, you really really DO want a chrome-lined barrel - esp if this is your first or 2nd AR.

They last much much longer and are much easier to clean. Feeding & extraction to/from chrome-lined chambers can be much better, esp for a wide variety of ammo. Most folks will not notice any accuracy difference, if at all.

CMMG chrome-lined barrels, esp the mid-profile and heavier profile ones, are known for stunning accuracy.

[adamsreeftank]

Armalite sells 16" barrels with mid-length gas ports. They carry stainless and chromoly barrels.

[bwiese]

Armalite sells 16" barrels with mid-length gas ports. They carry stainless and chromoly barrels.

They also have chrome-lined