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clearance between gas block and hand guard.


Dewberry

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how much clearance do I need between my gas block and hand guard?

I have a SLR ultralight hand guard and a SLR sentry 7 clamp on gas block the clearance between the bottom of the gas block and the inside of the rail is tight. If I put my thumb on the bottom of the rail and my fingers on my comp and squeeze with minimal effort I can feel the 2 touching. (with a spr profile fluted barrel) my concern is they will touch and effect accuracy when pushing into a barricade, or when I put a bipod on for target shooting.

Do I need to be concerned about this?

I figure my options are remove material from one of the 2 or get a new hand guard.

thanks in advance for the advice.

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I'd also like some HELP ;is there a certain amount of clearance that would be consider minimum, or optimum ; for instance a handguard with a overall of 1.63 and over the bore of .90 Using a gas block that is 1.40 overall and over the bore of .775 . Would this be considered to tight ?? As Dewbery mention just squeezing .

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Just for fun try getting it to touch by putting force only on the handguard. Barrels will flex some. I had to take a little material out of the inside of my HG to get some clearance. If I push/pull on the HG and barrel really hard I can get them to touch. If I only put force on the HG and don't touch the barrel (which is something I avoid doing when actually shooting anyway) there's no way in hell I can put enough force on the rifle against a barricade or rest to get them to make contact.

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Ive taken a 4" angle grinder to both my handguard and gas blocks before. Like Tony said, if putting it on a barrier and pressing on it makes it touch then worry about it. If not then its probably fine. Heat might play a role in contact as well.

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You need enough clearance to not make them touch under any kind of normal operating condition....it's not going to be a hard number, it'll depend on gas block size, handguard stiffness, etc. Touching with minimal effort is bad.

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To the original poster, what gas block does SLR recommend for use with their hand guard? The set screw only, or is the clamp on OK as well?

Todd at SLR will have the answer for you...

Mick

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To the original poster, what gas block does SLR recommend for use with their hand guard? The set screw only, or is the clamp on OK as well?

Todd at SLR will have the answer for you...

Mick

They told me both will work but it's a tight fit. But the set screw will give more clearance.

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I am going to go out on a limb here and say that depending on your build you will have different amounts of flex when it comes to your specific combination of parts.

Barrels that fit tighter in the upper would have a little less flex.

Lightweight barrels "whip" much more then a heavier barrel, and as such deflection to the hand guard is easier. As the gas block is the largest "part" of the barrel, that's what will make contact.

Some hand guards are more ridged then others. My Larue is quite rigid where as my troy HGs have a little more flex due to how they mount up.

The only way to "know" if your gas block is contacting the barrel is to use a high-speed camera of put some masking tape on the gas block, smooth it down good and fire several slow, well spaced out shots. You would be able to see if there is gas block contact based on wear marks on the tape.

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The only way to "know" if your gas block is contacting the barrel is to use a high-speed camera of put some masking tape on the gas block, smooth it down good and fire several slow, well spaced out shots. You would be able to see if there is gas block contact based on wear marks on the tape.

Thanks for the good idea.

Honestly right now the guns shooting sub moa at 200 so I'm just going to rock it and see what happens this weekend at the regional. Wish me luck. Haha

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