AR gas block

[Hickok]

While we are on the subject of AR's, (notice how I worked that in!) I am going to need a new gas block for an AR barrel I have coming, caliber 7.62 x 40, carbine length gas system. I have G.I. front sight/gas blocks but these have the cross pin type fixture. and I don't think this barrel will be set up for this type of gas block.

A lot of you guys have AR .300 BLK builds, so what do you recommend for a good gas block in .750" diameter? I will be using carbine length hand-guards, and don't need any front sight tower. Purely a scoped carbine.

[Mica_Hiebert]

Their all pretty much the same unless your wanting a adjustable gas block. I have used yhm low pro for a couple of free float builds.

[Hickok]

Thanks Mica, you must have read my mind. Here is a YHM I was looking at. Looks like a real easy install. http://www.jsesurplus.com/tworailgasblock-twopiece.aspx

This one looks good, but is out of stock, so I am going to look around for it.

http://www.jsesurplus.com/yhmlowprofilegasblockshort-1.aspx

[Electric88]

I've used the generic adjustable gas block from JoeBob Outfitters with good success. I have also used the adjustable gas block from SLR rifleworks, which is very nice.

Most of the basic low pro adjustable gas blocks are very similar and work well.

[6bg6ga]

https://rouschsports.com/shop/ar15-upper-parts/low-profile-micro-gas-block-aluminum-750/

[6bg6ga]

The Rousch sports gas blocks work fine

[Hickok]

Thanks guys. I settled on the YHM low profile with pinch screws. (finally found one). I have used gas blocks that were solid type before on a few AR barrels, and they can be a hateful tight fit. This YHM should slip on nicely.


160959

[Mica_Hiebert]

The ones I have used have been a pretty tight fit. A quick lapping with 600 grit and a little oil and they slide rite on. Mine where the set screw type tho so might be different with the pinch style.

[Preacher Jim]

i bought the last ones from a.i.m. surplus worked great fast delivery

[zubrato]

If removing an old gas block and you've got the tools and time, cut down the A2 gas block and touch up with oxpho blue, and pin back into place. This is the best way, and ironically the lowest profile gas block around.

If working on a new barrel, check for a barrel dimple underneath gas port. If the barrel is not dimpled, it's not too much work to dimple it yourself with a hand drill, punch pin/hammer, vise and a careful eye. Red loctite or Rocksett the threads.

Have not used the clamp style, but I'm sure they will be just fine as long as it's oriented properly (and it looks as though the bottom is drilled to help visualize the gas port). Most gas blocks have oversize ports to allow for some wiggle during the install.


As a final check before torquing down and red loctiting screws I put a foam earplug in the chamber, blow through the muzzle end and with finger on the end of the gas tube check for sufficient flow, or leaks.

enjoy your carbine!

[Hickok]

Zubrato :goodpost: Thanks for the pointers, and all you guys, thanks!

[popper]

I have dimple and slotted adjustable GB, neither is a problem. The slotted lets you use a screw driver to slide it on easier.

[C. Latch]

I cheat and only buy barrels from people who can pre-fit a block so that I only have to put them on and drive the taper pins in and be done.

[Hickok]

I have dimple and slotted adjustable GB, neither is a problem. The slotted lets you use a screw driver to slide it on easier.Popper that is what I was wanting to hear! I take it you use the screw-driver as a wedge in the slot.

If anyone can give me advice, experience, etc. on the 7.62x40WT, I am happy to hear it.

I did a search on the forum, but I can always use more info.

Case forming was pretty simple, I have 100 ready to load. Didn't completely full length size them yet, waiting on the barrel, then I can set the sizing die to get the shoulder/headspace right.

Lee dies and they work great.