Home CMMG How to Install a Gas Block Perfectly Straight Every Time

How to Install a Gas Block Perfectly Straight Every Time

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If you’re tired of struggling to install a gas block and ending up with crooked results, then this video is for you. In this walkthrough, we’ll show you the foolproof method we use to ensure a perfectly straight gas block installation every time. Whether you’re a seasoned builder or just starting out, this tip will make your life easier and your rifle more reliable.

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43 COMMENTS

  1. When I started building my own ARs, I bought an inexpensive gas block, drilled all the way through the block using the rear screw hole as a guide, then sharpened the rear of the drill bit so that I can use the bit to line up the gas block, snug up the front set screw and mount the barrel in my drill press vice.
    A couple light touches with the bit in the press starts the dimple just enough and it's dead straight, every time.

  2. This will work fine on high pressure rounds but low pressure rounds such as subsonic you need 100% of gas port and need to gauge gap off shoulder to have proper alignment. All my barrels that I will be running subsonic loads are gasport matched to gas block for 100% gas flow and 100% reliable operations in 300 blk and x39 platforms. I always pin in place for a solid connection.

  3. Or you can line it up using the rear set screw hole then take a pencil and draw a T-shaped index mark on the barrel. The will show you how far to push it in into the journal and where to line up the gas tube.
    Not sure how the video would show you to install the gas tube when you've got the block in place first.

    Another way that's not quite as precise but still works is to plug the chamber and muzzle then slide the block/tube assembly on. Use a can of compressed air and short squirts to give where the block is lined up with the port- you'll be able to tell by the sound. One the air is flowing, tighten the set screws.

  4. How to install a gas lock perfectly straight:

    1.) Install Gas tube into gasblock.
    2.) Insert Gastube combination onto torqued barrel.
    3.) Insert BCG followed by Charging Handle, set Bcg and charging handle into Closed/Locked position.
    4.) Look down the L.o.S from the gasblock to the Tube and ensure it is straight.
    5.) Tighten down Gasblock Keys
    6.) You are done. ASSEMBLE.
    7.) Functions Check.
    8.) Get to shooting.

  5. Pushing the gas block tight against the shoulder when there’s supposed to be a front hand guard cap would not be a good idea. You’re going to effectively cut off the amount of gas being pushed back. Running a suppressor? Might work. Other than that, having the gas port holes align perfectly is best.

  6. we want to see the next video, adding the gas tube… this is a cool series for everyone to learn… I know YT doesn't like these kinds of videos, but we appreciate them

  7. for the low price of 30$ and a hand drill, you can spend the same amount of time installing a dimpling jig, drilling a dimble, and installing your gasblock both perfectly square and center, and even more bomb proof.

  8. BA Hanson Barrels with the Low Pro makes install a breeze. The barrels are very accurate and durable. Dimpling and pinning is not necessarily hard if you have the rights jigs but at the price point of the BA Barrels it does not make much sense..

  9. Great info. I have always been curious as to why when the gas port is drilled in the block, it isn't drilled all the way through the the block? As this would allow indexing of the block using a pin gauge or other means during installation, eliminating the need for the coil pin. It also should not leak as the gas tube itself would obstruct the orifice. It seems like this would eliminate alignment issues potentially without adding any additional steps to the manufacturing process?

  10. In regards to your bench and assembly. When you drop a pin, do you just reach for another from those bins? Or do you get on your hands and knees cussing for the next five to ten minute before you call for your daughter who doesn’t have 50 plus year old eyes? Because that’s what I do…

  11. Does it matter much if the dimple for the gas block screw sets the block away from the shoulder just a little? I just installed an adjustable gas block on an 11.5 that I couldn't get the carrier to slow down enough with spring and weight alone…

  12. What would be great is if you guys could gas a .308” barrel accordingly. 16” modern series midlength is ridiculously overgassed. I had to close my adjustable block halfway just to get it to respond. I had already dimpled the barrel for .450” and the adjustable block was .475”

    Makes a guy a little pissy

  13. Luv BA Barrels! extremely happy with my LR 308 build using a Hanson Profile premium lopro. Had some trials at first getting it to cycle. had to open up the barrel gas port a couple thousands, but it cycles flawlessly now and unreal accuracy with a 18" barrel. Word of advice – USE BA's BOLT. THE BARREL AND BOLT WILL MATE PERFECTLY and you wont be cussing yourself for blowing your hard earned money on a generic bolt – ask me how i know. Looking to build my next one now:)

  14. Ok.. so… this video is pointless?

    You looked throught the set screw hole to see the barrel gas hole. Ok. Then you flip it over… you no longer know if you are vertical. The only thing you are doing here is saying if you buy a BA gas block and a BA barrel, line the pin up….

  15. I use a piece of angel hair spaghetti to line up the block and port. Stick a piece in your gas port and break it off flush. Slide gas port on, look look down the barrel, and rotate. When you get to sweet spot where the piece of spaghetti will slide in and out of gas port you're lined up perfectly. Tighten your set screws and use a cleaning rod to break the spaghetti.

  16. So do you install your gas tubes after the block is on the barrel and do it that way? Or if my barrel/block isn't pinned , should/can I install my tube to gas block then install the block & tube onto the barrel? is one better?

  17. Another "loctite"-er. Just get a dimpling jig, they are cheap. Then pin it. Rocksett the screws. This video is jabroni-esque advice. Furthermore, this won't get an FSB straight and this video only shows you how to get a low-pro "straight enough."

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