AR 15 Pistol need help on Buffer / spring tuning

[markshere2]

Himmmmm. I do believe someone somewhere mentioned it was undergassed.

Many people did.

You win the cement bicycle as the first prize for "I tolja So!!"

I was pretty sure it was, but wanted the cheapest fastest route if possible.

This time, not possible.

[DucatiRon]

Many people did.

You win the cement bicycle as the first prize for "I tolja So!!"

I was pretty sure it was, but wanted the cheapest fastest route if possible.

This time, not possible.

Actually USMC3531 gets first. I only nodded in agreement.

Still would have been pretty fast to pull of the forearm and check.

Live life as a mechanic. Test not guess.

[USMC3531]

While it is apart check the size of the gasport and compare with known working examples

[markshere2]

And here is the issue.

Lesson learned - don't use an aluminum gas block

aluminum gas block.jpg

[USMC3531]

Wow that's ugly, honestly with the gas cutting on it it appears to not have been aligned with the gasport.

[Gunsnwater]

Wow that's ugly, honestly with the gas cutting on it it appears to not have been aligned with the gasport.

Bingo! If it was aligned that wouldn’t have started. I use permatex gasket sealant (black oily thick not rtv) when putting on a gas block. If the upper is already built I don’t take it apart, I just let it alone. I use it when installing the gas key too.

[cdi]

Aluminum gas blocks roundly suck, that's why they're cheap.
Even hard anodized blocks leak and cause issues.

Aluminum expands and contracts very rapidly when it gets hot.
It doesn't come close to mirroring the steel barrel it's wrapped around.

[Emptymag]

Wow that's ugly, honestly with the gas cutting on it it appears to not have been aligned with the gasport.

So the "gouges" and misshapen hole are not casting issues? The hole being out of alignment caused all that deformation internally?

[marinville]

So the "gouges" and misshapen hole are not casting issues? The hole being out of alignment caused all that deformation internally?

The gas did that.

[Emptymag]

The gas did that.

Because it was trying to escape, but didn't have enough space to do so?
Wow.