Should I pin over set screw?

[Hulkstr8]

So I'm at the stage in my build where I am assembling the upper -specifically the gas block.

One of my barrels is a LaRue* Stealth which has three dimples and I have the matching gas block. Beefy.
Should I get this pinned? Thoughts? *sidenote: I am having an multi-month ongoing CS issue with them right now.

Another of my barrels is a Ballistic Advantage Hanson. Comes with a pinned gas block, but no dimples. Should I send it off to have it dimpled?

Lastly, I have a GMR barrel with no dimples or pins. I originally wanted a FSB install, but I can't find someone who will do it because the barrel is nitride'd. Should I dimple & pin? On this one I am using a nitride low-pro Brownell's gas block. Weird set spacing at .415.

What's the thoughts on dimpling? Pinning? Is it a must? - All of these rifles could potentially be duty use.

How can I make sure the gas block is properly aligned without the barrel being dimpled? Can I do any of this work myself -I haven't found anyone in the mid-Michigan area I trust anymore.

Sorry if my thoughts are varied and scattered -ADHD like a mother.

[tylerw02]

While I'm not the definitive authority on gas blocks, I've not ever seen a properly installed gas block set-screwed under a hand guard come loose. In fact, it's difficult to take off some factory installed gas blocks such as BCM.

I used to pin mine on no matter what; and while it's the most bomb-proof way to install it, it's overkill.

All exposed gas blocks or FSBs need pinned, no exception.


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[Hulkstr8]

Thanks for the advice.

A guy I know and whom I trust advised that a pinned gas block would allow less gas to escape than a set screw. I'm not sure if this makes sense to me?

[tylerw02]

I've never heard such a thing, myself. I don't know how that could be possible. A quick search doesn't come up with anything to verify that.


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[26 Inf]

Could be your friend is thinking that the pressure from the set screws would pull the block tighter against the barrel contour thus providing a better seal. Don't know if that is true or not, just an idea.

Reference your original post - if the gas block is pinned it does not need to be dimpled, so that BA Hanson barrel should be good to go.

Dimpling the barrel for a gas block is not that difficult. I've posted these instructions for installing a Geissele Super Gas Block several times in the past, they explain the process:

https://geissele.com/media/files/super-gas-block-ai.pdf

You can also by a dimpling jig from SLR Rifleworks: http://slrrifleworks.com/index.php?r...product_id=579

Use the search function for 'barrel dimpling' and you'll find several threads.

[Rayrevolver]

I believe ADCO will dimple opposite the gas port when installing the GB prior to drilling the pin.

It wasn't long ago that this forum was adamant about pins, but that has softened probably based on BCM performance. I have had a few BCM uppers without pins and no issues.

For me, I had ADCO pin my set screw GB. Belts and suspenders!!!

[hk_shootr]

I've never heard such a thing, myself. I don't know how that could be possible. A quick search doesn't come up with anything to verify that.


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Geissele
Superlative
Ballistic Advantage
Syrac

[hdrolling]

If you own a drill and bits then just buy a jig and dimple your own barrel, they cost less than $40. I paid $35 for my SLR dimple jig, on one side it lines up on your gas port hole so on the other side the dimples are drilled in the perfect spot.

[Hulkstr8]

Geissele
Superlative
Ballistic Advantage
Syrac

Could you explain further?

How important overall is dimpling or pinning?
Also, I might give a shot at ADCO. I'm only an hour and half drive away.

[Hulkstr8]

If you own a drill and bits then just buy a jig and dimple your own barrel, they cost less than $40. I paid $35 for my SLR dimple jig, on one side it lines up on your gas port hole so on the other side the dimples are drilled in the perfect spot.

Cool. I need to buy a drill press soon. Either way I would go BRD or SLR.