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Dirtbiker
04-24-2008, 11:05 AM
There is a lot of talk how the carbine length gas system is hard on internal parts. Does anyone make an adjustable gas block for the AR series? Or how about an adjustable gas system with an attached/attachable front sight?

mikecro1
04-24-2008, 11:11 AM
you mean like this???:D

http://i29.photobucket.com/albums/c265/urban_jedi/IMG_0366.jpg

...:p jk:D this is my "adjustable" gas piston AR....the "Mikesada"

kinda different from direct impingement but there is absolutely nothing wrong with the traditional DI carbine length system...my ...02 cents.

aplinker
04-24-2008, 12:02 PM
There is a lot of talk how the carbine length gas system is hard on internal parts. Does anyone make an adjustable gas block for the AR series? Or how about an adjustable gas system with an attached/attachable front sight?

Yes, but it doesn't cure the issue.

http://www.midwayusa.com/eproductpage.exe/showproduct?saleitemid=754025

Dirtbiker
04-24-2008, 1:18 PM
Yes, but it doesn't cure the issue.

http://www.midwayusa.com/eproductpage.exe/showproduct?saleitemid=754025

Plinker, why not?

If the system is overpressured due to short gas length I'd assume that limiting the gas pressure would clear up the issue. What am I missing?

aplinker
04-24-2008, 2:05 PM
Plinker, why not?

If the system is overpressured due to short gas length I'd assume that limiting the gas pressure would clear up the issue. What am I missing?

Think of it this way... if pressure were the only issue, that could be "fixed" by adjusting the hole size on all rifles.

Adjustable does help to "fix" the pressure problem, but there are other problems with carbines - like the dwell time - that the adjustable gas block wouldn't change.

Also, when you dial in to reduce the pressure you can make it less adaptable, so that ammunition changes can cause it to not work well (like switching from 5.56 to softer .223 loads).

Why not go mid-length?

J_Rock
04-24-2008, 2:07 PM
Why not go mid-length?

Exactly, adjustable gas blocks are only useful if you are firing suppressed

ar15barrels
04-24-2008, 8:05 PM
Plinker, why not?

If the system is overpressured due to short gas length I'd assume that limiting the gas pressure would clear up the issue. What am I missing?

Dwell time.

aplinker
04-24-2008, 9:13 PM
Dwell time.

Have you tried the pig-tail gas tubes and seen if that fixes it? Seems like an expensive fix at about $100, regardless, when building a mid-length is such a no brainer for anything but an ultra-shorty

ar15barrels
04-24-2008, 10:55 PM
Have you tried the pig-tail gas tubes and seen if that fixes it? Seems like an expensive fix at about $100, regardless, when building a mid-length is such a no brainer for anything but an ultra-shorty

The issue with pigtails is that they bend with temperature change and cause gas tube alignment issues.
The PRI fatboy gas tube is a better solution.

Dirtbiker
04-25-2008, 10:41 AM
I have not had any problems, just hoping to avoid wear and tear. Thanks for all of the expert advice.

My next build will be a mid or rifle or 9mm or spr or precision or 6.8 or Grendel.

There are so many fun choices!!! I need a better job.

grywlfbg
04-25-2008, 5:14 PM
I have adjustable gas blocks on my competition rifles (http://jprifles.com/1.4.6.php). It can make a huge difference in terms of felt recoil (a lot of the recoil you feel is the buffer slamming into the end of the stock).

But these are "race guns" so reliability isn't of primary concern (although I've never had any problems) and I reload so I'm always using the same spec ammo.