Gas block installation

[jeffreyliu838]

I installed this gas block a while ago and haven't really thought about it but I was just pondering the way I installed it and I want to make sure I did it right.

What I did was I slid the gas tube into the gas hole (is that the right nomenclature?), pushed it in and cranked down on the set screws. I installed a YHM gas block/flip up front sight post.

I didn't jam it in there with pressure or anything, but I put the gas tube into the upper as far as it would go it and then screwed on the fsp/gas block. I didn't loc tite it since I figured the gas block would burn it off anyways. I was thinking about staking the screws, but I wouldn't know how to remove it if I did that.

I have shot it and it shoots, but I just want to be sure.

Thanks.

[SJgunguy24]

Drill into the barrel slightly and make a divet so the set screws have something to lock into. Then lock tight and your good.

[jeffreyliu838]

I didn't know what the true definition of a set screw was in the original post. I guess these aren't really set screws after all, I just looked it up.

http://yhm.net/index.php?main_page=product_info&cPath=2_3&products_id=3

This is the fsp I have.

I did install it correctly though. Right? Or at least safely? Just slide the gas tube into the upper as far as it'll go and screw it down?

[NewbieDave]

Just make sure you pinned the gas-tube... that's what that little hole on the side is for. If not, you're going to get a shifting tube and gas leakage. Don't crank those hex screws too hard... 25-30 lbs if all you need to set those. Those screws will snap if you crank them too hard, saw that happened at a shop once when the "armor" was trying to install one of these.

[jeffreyliu838]

You mean pinned the gas tube as in pinned it to the gas block? That's done.

I'm most worried about the spacing between the gas key and the gas tube. I'm wondering if I might've screwed that up. and if my gas block is actually properly lined up with the port on the barrel.

[NewbieDave]

You should be indexing the gas block with the shelve of barrel... but if you want to double check, mark on the side of the gas block where the gas hole is, mark another line on the barrel where that gas hole is... align the two lines and you are good.

As for if it's squared... fold your sights down and flip it upside down on a flat table. Use paper to prop up the receiver side until everything sits flat, than you know it's flat on the top.

[jeffreyliu838]

What is the shelf of the barrel?

[jeffreyliu838]

Would like some advice on how to keep it from coming loose too.

Again, this is the fsp I have.

http://yhm.net/index.php?main_page=p...&products_id=3

[Falstaff]

What is the shelf of the barrel?

Me too! What's that mean?

I always worry about getting the gas ports lined up perfectly, so what I do is plug the barrel and pressurize it while adjusting the gas block and listening for maximum flow.

[NewbieDave]

See where the barrel taper from thick to a thinner profile, it just drops off... that's the shelf that you index your gas block on. You really can't push it farther down the barrel because of that edge.

As for your gas hold, if you want to make sure that it's lined up... shoot some Breakfree PowderBlast into the gas tube from the receiver side, it'll leak out easy into your barrel if everything's limed up.