Barrel and Gas Block????

G

gene10pntr

New member
I have a .223 barrel that doesn't have dimples drilled in the bottom for the block set screws...are most barrels drilled or smooth like mine? Can I use either kind of block or do I need the clamp on type low profile .936 for mine. It's a heavy barrel and want to use a rifle length or longer guard if I can find one I like???
Thanks....
Gene
 
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Many manufacturers dimple the barrel but not all. No problem using either block on non-dimpled. Lining up the hole can be a challenge for some. Two things to remember that on 90% of the blocks they DO NOT go back against the shoulder on the barrel. They are usually held off the thickness of the forearm cap, about 0.030 or 1/32 IIRC, to line up properly. Also on the blocks the rear screw is drilled directly below the gas port hole so that will let you line it up by measuring distance from shoulder to middle of gas port and then setting your screw the same distance off the shoulder.

Personally on non-dimpled I think the clamp on would be the way I would go. I have both and have had no issues with either and it's just my preference.

Greg
 
i have a .936 clamp on that came with my WOA and i put a rifle length guard over it. went with a samson evo. fits like a champ. its not a ton of clearance, but its about like free floating a barrel in a stock - i can easily slide a business card in there.


there are some micro gas blocks that are made for .936 gas block journals

JSE has a couple different models available.
http://www.jsesurplus.com/936.aspx

joebobs has the SLR adjustable, but i dont know if that'll fit under your handguard as its a bit tall at 1.63"
http://www.joeboboutfitters.com/SLR_Sentry_9_Clamp_On_936_Premium_Adjustable_Gas_p/slr-sa9-cm.htm


bte offers one in both adjustable and non adjustable models
http://www.bte-usa.com/#!bte-set-screw-micro-gas-blocks/c110e


HTH
 
Most barrels don't come dimpled as the spacing on gas block set screws can vary a bit as can the gas block seating on barrels. You don't 'need' to dimple the barrel. If its hidden under a handguard then its a moot point, IMO.

Originally Posted By: Plant.Onejoebobs has the SLR adjustable, but i dont know if that'll fit under your handguard as its a bit tall at 1.63"
http://www.joeboboutfitters.com/SLR_Sentry_9_Clamp_On_936_Premium_Adjustable_Gas_p/slr-sa9-cm.htm

The SLR gasblocks should fit under any AR15 handguard, as far as we've ever come across.
 
Thanks for all the great replies and information!!! This is only my second build and was just curious because my first barrel was dimpled...so I just assumed they all were. Now I know I have an assortment of blocks to choose from...
Thanks again AR shooter's and builder's...
Gene
 
good luck with your build!


i'm sure i'm not the only one who would like to see pics of the finished product!
smile.gif
 
I use clamp on for all of my builds anyway. Set screws work, but I like the idea of pulling a consistent contact around the barrel with a clamp on style, rather than pressing a gap open at the bottom just to pull the top tight.

You can't always count on the dimple to position the block properly - it could be mis-located, or the port itself mis-located, or the port within the block could be mis-located. I let the gas block tell me where it wants to be positioned. I use an empty case with a spent primer to seal the chamber, then blow into the muzzle while sliding the gas block back and forth and turn it over the port. I can feel the position which gives the least resistance to flow, and that's where I lock it down. I'll then fire a few shots, put a timing mark on the barrel and block, pull it off, and look for any powder witness residual on the block or the barrel.
 
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