Putting together an upper

FortyMikeMike · Jun 6, 2015

I'm piecing together the tools and small parts I'll need to assemble an upper from scratch for the first time.

I've got an upper receiver, 18" barrel, and rifle gas tube from Nordic. Soon I'll be ordering a Diamondhead VRS-T handgaurd to go over it all.

My main question right now is about what gas block to use. I'm thinking the clamp on kind would be best since the barrel isn't dimpled for a set screw type. Anyone have any experience with what fits under the VRS-T handgaurd? Also, what size roll pin do I need for the gas tube?

FortyMikeMike · Jun 6, 2015

One more thing: I've read the torque for the barrel nut is 35ft/lbs with a max of 80ft/lbs, but that seems pretty broad, what do you all use? As I underatand it, the barrel nut that comes with the VRS-T doesn't need to be lined up for the gas tube so I can set whatever torque and be done with it.

Wildcat · Jun 6, 2015

I torque mine and back it off 3 times to 35 ft/lbs then final torque to a max of 80 to line up the barrel nut and tube. If you don't need to align the nut stop somewhere between 35 and 80.

mike cyrwus · Jun 6, 2015

^^ good advice.

FortyMikeMike · Jun 7, 2015

Good to know, thanks.

Anyone have anything against clamp on gas blocks? I don't feel like dimpling my barrel for a set screw.

Podman · Jun 7, 2015

I've used clamp on gas blocks with no problems so far. I haven't shot all that many rounds though through my ar-15's. I suppose if they don't work out in the long run I can
replace them with something else

Matt1911 · Jun 7, 2015

I've used several of the set screw gas blocks with success.

FortyMikeMike · Jun 7, 2015

At first I was worried the handgaurd I'm wanting was too narrow for a lot of the gas blocks out there but I finally found some internal dimensions today and it looks like there's plenty of room.

I think I'll order a Yankee hill clamp on; good reviews, not expensive.

wgm2011 · Jun 7, 2015

You may already know these, but just in case:

On the upper receiver threads, spread a nice glob of anti-seize (from the auto parts store) before installing the barrel nut. Torque as recommended above.

Install the gas tube to the block before installing it to the barrel. (Yup, I've seen folks forget this one but its the easy way to do it.)

When installing the clamp-on gas block, slide it on as far as it will go and then set it forward with a slight gap between the block and the ridge on the barrel. I usually slip a credit card into the gap and that seems to be just right.

I've used several Yankee Hill gas blocks without complaint.

Bill

charger arms · Jun 8, 2015

MikeF said:
At first I was worried the handgaurd I'm wanting was too narrow for a lot of the gas blocks out there but I finally found some internal dimensions today and it looks like there's plenty of room.

I think I'll order a Yankee hill clamp on; good reviews, not expensive.

I have removed all the YHM gas blocks from my carbines. They seem to leak more gas as shown by the carbon streaks on the barrel. Also, they leak out the front hole for the gas tube. I have recently started using SLR gas blocks. They make a non-adjustable version that fits like a glove. It is the set screw version. If you know how to use a set screw, you won't need dimpled barrel.

I had to grind the inside of a Midwest Industries hand guard to clear the Carbon Arms side clamping gas block.

FortyMikeMike · Jun 8, 2015

Thanks for the input everyone.

I've got some Aeroshell 33MS to use on the barrel nut, didn't know about the gap with the gas block though...

Might have to rethink YHM, seems like I'm getting more mixed feedback on them. I know the one vltor makes will fit too, its just a bit more expensive.