Stag 3H Upper - Rail Install

[s2000news]

Hello all,

I need some help/advice on a Rail install.

I have a Stag 3H Upper and want to install a YHM-9479 Rail (Carbine).

First off, I read the instructions (pdf link below) and wanted to make sure that this install was possible with this upper.

Any advice is greatly appreciated.

Bryan





PDF Instructions

Removal and Install instruction help link.

[ar15barrels]

I have not had any luck being able to un-install rain when I want to.
It seems we are all at mother nature's mercy.
Get a raincoat.

[s2000news]

I have not had any luck being able to un-install rain when I want to.
It seems we are all at mother nature's mercy.
Get a raincoat.

Haha. Comedians...

Fixed it!

[ar15barrels]

No problem to install that rail on your stag.
You are going to need an armorer's wrench and a YHM wrench though.
Your gas block comes off with the two socket head cap screws.
Your original barrel nut comes off with the armorer's wrench.
The YHM barrel nut goes on with the YHM wrench.

[s2000news]

No problem to install that rail on your stag.
You are going to need an armorer's wrench and a YHM wrench though.
Your gas block comes off with the two socket head cap screws.
Your original barrel nut comes off with the armorer's wrench.
The YHM barrel nut goes on with the YHM wrench.

Thanks.

YHM wrench I do not have. Anyone sell those that you can reccomend? I'll start looking for one.

[s2000news]

While reinstalling the gas block, it appears as if it is pulled out just maybe a 1/16 inch. Based on the marks on the barrel. Sound right, or should it be pushed as far in as it goes? The tube is making it back to the BCG, but does that small about make a difference?

[ar15barrels]

While reinstalling the gas block, it appears as if it is pulled out just maybe a 1/16 inch. Based on the marks on the barrel. Sound right, or should it be pushed as far in as it goes? The tube is making it back to the BCG, but does that small about make a difference?

As you are no longer using the handguard cap, you still need to account for it when you position the block.
It's important that the block gets installed with about a 1/32" gap behind it where the handguard cap used to be.
This will locate the gas port in the gas block right over the gas port in the barrel.
If you mis-align the gas block enough, you can actually shut down the gas flow enough to cause function problems.

[s2000news]

As you are no longer using the handguard cap, you still need to account for it when you position the block.
It's important that the block gets installed with about a 1/32" gap behind it where the handguard cap used to be.
This will locate the gas port in the gas block right over the gas port in the barrel.
If you mis-align the gas block enough, you can actually shut down the gas flow enough to cause function problems.

Thanks,

Malfunctions it did. However not always.

I installed the block in the middle of the mark, and all the way back. I didn't have any real issues for the first 100 rounds. Then, (same ammo) I seemed to have issues out of no where. The round would fire, eject the casing yet not chamber the next round, or not fully chamber the round, only catching the round in the mag.

At first, I thought maybe the cleaning job wasn't the best, as it worked just fine for the 100 rounds, but now I'm thinking maybe the port was blocked enough that the bolt didn't get enough recoil to catch the next round in the mag? Seemed to have more empty chambers than anything. At a ratio of 40% failed to chamber a round from shots 150-300.

Thoughts?

[ar15barrels]

Thanks,

Malfunctions it did. However not always.

I installed the block in the middle of the mark, and all the way back. I didn't have any real issues for the first 100 rounds. Then, (same ammo) I seemed to have issues out of no where. The round would fire, eject the casing yet not chamber the next round, or not fully chamber the round, only catching the round in the mag.

At first, I thought maybe the cleaning job wasn't the best, as it worked just fine for the 100 rounds, but now I'm thinking maybe the port was blocked enough that the bolt didn't get enough recoil to catch the next round in the mag? Seemed to have more empty chambers than anything. At a ratio of 40% failed to chamber a round from shots 150-300.

Thoughts?

Check if the gas block slid forward during use.

[s2000news]

Check if the gas block slid forward during use.

No, no visible movement.

After returning from the range yesterday, I decided to move it back, (up) to the marks on the barrel where I think it was before.

Test to be performed next.

Any good cleaning videos you know of on youtube for upper cleanings? I have seen the general one, for the lower, but not any real time showing any upper cleanings.

Thanks

[ar15barrels]

Any good cleaning videos you know of on youtube for upper cleanings?

I don't clean m AR's.
I just add oil before each use.
When they actually get sluggish enough to malfunction from all the build-up, then I clean them.
This usually seems to be around 1000 rounds for me.

[s2000news]

I don't clean m AR's.
I just add oil before each use.
When they actually get sluggish enough to malfunction from all the build-up, then I clean them.
This usually seems to be around 1000 rounds for me.

Okay, sounds good to me.

I normally clean the lower after each shoot. But then again I go through 400 rounds. Tend to have a few people that want to shoot it.

But.... thanks for the info. I will have to read up on Gas Blocks a bit more.

[s2000news]

Thanks for the help AR15, here is the finished product.

I still need to cut the rail guards to length, but you get the idea. I ordered the cap as well for the float rail, install that next.

Notice the gas block... see that barrel mark, it was there even BEFORE I installed the rail. Weird, but I didn't notice it before.