Aluminum Gas Blocks

[Oz]

There are AR-15 aluminum gas blocks all over the place.  And in my quick search, I've seen quite a few aluminum 308 gas blocks.  Does anyone know of any problems or concerns with aluminum 308 gas blocks?

[392heminut]

As far as I know, AR15 and AR308s gas blocks are interchangeable, the only variation is the size. That being said, my DPMS LR308 came from the factory with an aluminum gas block.

[imschur]

A good friend who was an engineer at a firearms manufacturer that worked on FAL's explained to me that based on the volume of gas associated with the .308 that the block will erode faster than with a 5.56.

Probably not a big deal if your using your weapon for hunting and casual shooting but if you shoot A LOT it could be an issue.

[Jgun]

I've read on one of the barrel makers site's were they don't recommend the aluminum GB's because of the fact that the aluminum GB and steel barrel expand at a different rate and you can have gas leakage. Based on all of the aluminum blocks on the market, maybe that's untrue. If you decided to run one you could always plan to replace it when you replace your gas tube.

[ErikS]

Gas leaks from all over an AR.  They kinda work that way. A bit from the front won't matter and the carbon will seal much of it after a hundred rounds or so.

[Oz]

Thanks y'all.  Great info here.

[survivalshop]

Unless you are pulling it off every time you clean your rifle , they will all seal eventually.

I personally like steel clamp on type .

[Jgun]

I've also read that if ultimate accuracy is your goal from the AR, the set screw mount type GB's are not ideal, because they create localized pressure at two points on one side of the bore. I'm not sure how tight you need to torque the set screws on the GB's so this may not really be an issue, but I think that the clamp on, or Noveske's pin on mounting method are probably superior.

[survivalshop]

I've also read that if ultimate accuracy is your goal from the AR, the set screw mount type GB's are not ideal, because they create localized pressure at two points on one side of the bore. I'm not sure how tight you need to torque the set screws on the GB's so this may not really be an issue, but I think that the clamp on, or Noveske's pin on mounting method are probably superior.

It is also said that the std. taper pins on an AR , also do the same .