Gas block touches rail.

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[ARCHIVED THREAD] - Gas block touches rail.

Posted: 2/11/2017 8:10:21 PM EDT

Is this a problem? It barely makes contact at the very front. It seems to shoot ok. I had a hard time finding a gas block that would fit on this larue stealth barrel. I think this is a yankee hill gas block

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Posted: 2/11/2017 8:21:34 PM EDT

[#1]

I do believe you have now un-free floated your barrel.

Posted: 2/11/2017 8:25:32 PM EDT

[#2]

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Quoted:
I do believe you have now un-free floated your barrel.

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is this a super huge issue?

Posted: 2/11/2017 8:30:06 PM EDT

[#3]

Will or cause the rifle to fail? No
Will it effect poi and maybe beat against the hg while firing? Maybe

Looks like a clamp on block, if hg clearance was an issue a set screw gb might have been better, they tend to be a little smaller in that area

Posted: 2/11/2017 8:30:11 PM EDT

[#4]

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Quoted:
is this a super huge issue?

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Not a huge issue. Little scratching to the rail and losing the benefits of free floating. Not sure about long term though but doesn't seem likely to cause problems.

Posted: 2/11/2017 8:33:58 PM EDT

[#5]

Quote History

Quoted:
Will or cause the rifle to fail? No
Will it effect poi and maybe beat against the hg while firing? Maybe

Looks like a clamp on block, if hg clearance was an issue a set screw gb might have been better, they tend to be a little smaller in that area

View Quote

I tried three of those at the gunshop and they would not fit the profile of the barrel. Would not fit on

Posted: 2/11/2017 9:02:06 PM EDT

[#6]

What kind of gas block are you using? Pretty sure it's a .750 gas block journal. Plenty of low pro gas blocks out there that should fit. Why not buy online rather than force a non-solution if there aren't any options available locally?

Edit: Are you sure the gas blocks you tried at the gunshop were .750? Maybe your journal is out of spec?

Posted: 2/11/2017 9:02:25 PM EDT

[#7]

can you just pull off the gas block and use a few passes of a file till it clearances?

Posted: 2/11/2017 9:04:11 PM EDT

[#8]

Quote History

Quoted:
can you just pull off the gas block and use a few passes of a file till it clearances?

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file the block? How much clearance do you need? All the other sides are like paper thin spaces

Posted: 2/11/2017 9:28:33 PM EDT

[#9]

Quoted:
Is this a problem? It barely makes contact at the very front. It seems to shoot ok. I had a hard time finding a gas block that would fit on this larue stealth barrel. I think this is a yankee hill gas block

https://www.AR15.Com/media/mediaFiles/296004/IMG-0645-144898.JPG
https://www.AR15.Com/media/mediaFiles/296004/IMG-0643-144899.JPG
https://www.AR15.Com/media/mediaFiles/296004/IMG-0647-144905.JPG

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You do know that LaRue Tactical has a gas block to go with these barrels do you not?

LT low profile gas block

Posted: 2/11/2017 9:33:20 PM EDT

[#10]

Quote History

Quoted:

You do know that LaRue Tactical has a gas block to go with these barrels do you not?

LT low profile gas block

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.625 or .75? The barrel does not say

Posted: 2/11/2017 9:37:15 PM EDT

[#11]

There are several issue.

1. The barrel whips when shot beaning the barrel flexes and thus the gas block will be now be contacting the hand guard even more effecting point of impact.

2. When holding the hand guard, because its free float its able to move around slight without touching the barrel. However, when it comes in contact with anything on the barrel and the guard leans on the barrel the barrels accuracy is now effected.

I dont know how much your going to notice this. I have seen some people grind away the inside of the rail however that can be hard with its deep inside the rail. I have to figure something out for my build as well the adjustable gas block I choose touches at the top section just a bit or doesnt. Either way I want more clearance so its not possible to effect the accuracy.

Posted: 2/11/2017 9:40:35 PM EDT

[#12]

Stealth is .750

Posted: 2/12/2017 12:43:49 AM EDT

[#13]

Order a quality .750 set screw LPGB and call it a day.

DD, Vltor, v7, BCM, Geissele, etc. are all good choices.

Posted: 2/12/2017 12:54:26 AM EDT

[#14]

Use calipers to measure your barrel OD. Then buy a quality gas block.

Sure, you can shoot it as-is, but it's fairly in-intelligent to do so, considering how far into this you are.

Posted: 2/12/2017 1:05:40 AM EDT

[#15]

I have seen accuracy issues from every situation like this.

IMHO, you will never be able to make use of the full accuracy potential ....until the "touching" is fixed... completely

Posted: 2/12/2017 1:06:23 AM EDT

[#16]

Personally, I'd see where exactly it makes contact and grind it down some, even if the bottom. Point is, you don't want contact with a FF tube. Then cold blue. Alternate route is a different GB like a MI micro, which will leave room, have 3.

Posted: 2/12/2017 6:36:00 PM EDT

[#17]

Well I will take the block back to the gun store I got it from. If they don't have one there that will work I will buy the $70 larue one. The one that's on it is $40

Posted: 2/12/2017 6:39:49 PM EDT

[#18]

Quote History

Quoted:
Well I will take the block back to the gun store I got it from. If they don't have one there that will work I will buy the $70 larue one. The one that's on it is $40

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Honestly on the LaRue Stealth I had, I just used the cheapest gas block I found. The $20 Radical Firearms gas block from Primary Arms fit perfect and the two screw holes lined up with the first and last dimple on the barrel.

http://www.primaryarms.com/radical-firearms-low-profile-gas-block-750-set-screw-style-rf-750_2

Posted: 2/12/2017 8:19:59 PM EDT

[#19]

If it was mine all i'd be worried about is its effect on barrel harmonics or "barrel whip"

Personally i'd file down the corner of the block or the section of rail its touching unless money isn't an issue, then lower profile block

Posted: 2/12/2017 8:27:41 PM EDT

[#20]

Quote History

Quoted:
Well I will take the block back to the gun store I got it from. If they don't have one there that will work I will buy the $70 larue one. The one that's on it is $40

View Quote

LaRue's is probably still back ordered. SLR makes one that fits. You want the .450 set screw spacing to match the barrel.
http://slrrifleworks.com/index.php?route=product/product&path=57_103_65&product_id=654

Posted: 2/12/2017 8:57:49 PM EDT

[#21]

This is why I make my own low profile gas block from a FSB.. I can make it fit any rails and its uses the original pins sop its never going to give me a problem.

And yeah, if you don't fix it, your going to have accuracy issues.

Posted: 2/13/2017 7:22:06 PM EDT

[#22]

I took it back and got the Midwest industries gasblock. Not touching at all.

[ARCHIVED THREAD] - Gas block touches rail.

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