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Posted: 4/7/2016 4:49:19 PM EDT
| So i bought a jig from slr rifleworks to dimple my barrel, not realizing gas block mounting holes are differently spaced apart depending on manufacturer. I need to dimple my barrel which is .625. I'm using the battle arms gas black and the slr jig uses a 5/32 bit instead of 11/64. The 11/64 will not fit in the jig. Can i start the hole with the 5/32 then remove jig and finish with 11/64? Also, the second hole won't match up because it's not made for a battlearms gas block. Can i just dimple the one hole directly under the gasport (use as a reference)and mount my gas block with set screw then using a pencil mark where to start the second hole? all because it's .460 and the jig only goes up to .450 (guess that's what slr's gas blocks are). I hope i'm explaining this right ? any help will be appreciated. |
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So i bought a jig from slr rifleworks to dimple my barrel, not realizing gas block mounting holes are differently spaced apart depending on manufacturer. I need to dimple my barrel which is .625. I'm using the battle arms gas black and the slr jig uses a 5/32 bit instead of 11/64. The 11/64 will not fit in the jig. Can i start the hole with the 5/32 then remove jig and finish with 11/64? Also, the second hole won't match up because it's not made for a battlearms gas block. Can i just dimple the one hole directly under the gasport (use as a reference)and mount my gas block with set screw then using a pencil mark where to start the second hole? all because it's .460 and the jig only goes up to .450 (guess that's what slr's gas blocks are). I hope i'm explaining this right ? any help will be appreciated. Yes, what you describe should work fine, just take your time and get the marks right. The 5/32 will be fine - you are just trying to "dimple" the barrel to prevent the gas block set screw from moving. Once you get the first dimple drilled, you can position the gas block and mark the second hole. |
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all makes sense, i appreciate all the help, i didn't realize people only put one screw in. No, most people don't dimple for both screws. The dimple is almost entirely to locate the gas block in alignment with the gas port. Seriously, that's ALL it's designed to do. As a beneficial side effect, the dimple helps the screw opposite the gas port dig in a little better, for better retention. DEFINITELY install BOTH screws, and torque them accordingly. I use the longest "L" shaped Allen wrench in that size that I can find, and apply hand pressure until nothing moves anymore. After that, use some technique for retaining BOTH screws - I stake mine, but some folks use Rockset or extra-high temperature thread-locker. |
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Also be aware that you probably have to leave a small gap where the hand guard cap would normally fit. If your jig indexes into the gas port you shouldn't have a problem, it makes sure you are lined up right. In my experience, none of the aftermarket blocks I have used ever needed to be spaced. If you space them, they have an overhang on the barrel journal, and they all worked fine pushed all the way back. |
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No, most people don't dimple for both screws. The dimple is almost entirely to locate the gas block in alignment with the gas port. Seriously, that's ALL it's designed to do. As a beneficial side effect, the dimple helps the screw opposite the gas port dig in a little better, for better retention. DEFINITELY install BOTH screws, and torque them accordingly. I use the longest "L" shaped Allen wrench in that size that I can find, and apply hand pressure until nothing moves anymore. After that, use some technique for retaining BOTH screws - I stake mine, but some folks use Rockset or extra-high temperature thread-locker. Quoted:
Quoted:
all makes sense, i appreciate all the help, i didn't realize people only put one screw in. No, most people don't dimple for both screws. The dimple is almost entirely to locate the gas block in alignment with the gas port. Seriously, that's ALL it's designed to do. As a beneficial side effect, the dimple helps the screw opposite the gas port dig in a little better, for better retention. DEFINITELY install BOTH screws, and torque them accordingly. I use the longest "L" shaped Allen wrench in that size that I can find, and apply hand pressure until nothing moves anymore. After that, use some technique for retaining BOTH screws - I stake mine, but some folks use Rockset or extra-high temperature thread-locker. On my buddy's LaRue Stealth barrel, there were dimples drilled for each set screw (3) on their gas block. |
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On my buddy's LaRue Stealth barrel, there were dimples drilled for each set screw (3) on their gas block. Quoted:
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all makes sense, i appreciate all the help, i didn't realize people only put one screw in. No, most people don't dimple for both screws. The dimple is almost entirely to locate the gas block in alignment with the gas port. Seriously, that's ALL it's designed to do. As a beneficial side effect, the dimple helps the screw opposite the gas port dig in a little better, for better retention. DEFINITELY install BOTH screws, and torque them accordingly. I use the longest "L" shaped Allen wrench in that size that I can find, and apply hand pressure until nothing moves anymore. After that, use some technique for retaining BOTH screws - I stake mine, but some folks use Rockset or extra-high temperature thread-locker. On my buddy's LaRue Stealth barrel, there were dimples drilled for each set screw (3) on their gas block. When you're using a jig to drill your own barrel, you may, or may not, decide to do the second screw, keeping in mind that not all jigs cover all possible gas blocks. LaRue dimples for their blocks because Mark is thorough.  But while it's handy, it's not absolutely needed.
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I never bothered. Dimpling is added security. The barrels that I have that were not dimpled from the factory, still have the gas block securely in place. I have a Kreiger barrel from Compass Lake Engineering. When I ordered it, I had them ensure their gas block that I odered with the barrel would fit without having to sand the inside the gas block (I had a DD and and a badger that would not fit, even after using heat). CLE dimpled the barrel and their gas block was all the way to the lip without a gap, where the dimples would align with the gas block. Runs perfectly fine, as well with a few others I've built without leaving a small gap. |
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