Home Forums Hunting & Shooting AR and Tactical Rifles Upper Project, 16" Mid-length HBar

OK, time to get back to this project and finish it up.

I ended up picking up a YHM Diamond free-float quad rail. So I'll be knocking the pins out of the FSB to put it on. no biggie, I've done it a few times before. Already have the pins soaking in Kroil.

I upgraded from my basic tools (barrel blocks/armorers wrench). Bought a Magpul Bev Block, and a PRI barrel nut wrench. Should make things go pretty smooth.

I'd saw off the the sight,retain the pinned 'block and drive a FF tube that covered same.

That thing even looks loud.....................(grin)

if you weren't aware, use a big punch to start the pins. lotsa folks try to start 'em with a tiny pin balanced and it goes badly. (grin)

Screw the punch, push them in with a pair of Knipex smooth jaw pliers so much faster and easier. I put tape on the jaws it helps keep the pin from moving and gives protection to the metal once you make contact.

A block or clamp to hold the upper is useful too...................

MM

I was referring to removal. Pliers don't really work for that.

MCH just woke up a little early & confused today

Cut him a little slack..........................

MM

I always use a big punch to loosen the FSB pins. Like I said, I've done it a few times.

I can't hear ya, my ears are ringing......grin

The Bev Block does stabilize the upper. It locks in to the barrel extension, and the bolt carrier slides over the aft of the Bev Block.

Here's a decent little vid that explains the Bev Block, and the Reaction Rod,

I LOVE pinned 'blocks...but Loudeners hurt me................

hey it happens.

Here's a pic of the upper receiver, set up in the Bev Block, pulled off the muzzle device first.



Pulled the gas tube, then laid down the FSB on a wooden block to knock the pins loose. One good rap is all it took, after soaking in Kroil overnight.



Back in the vise to remove the FSB and swap out the old barrel nut for the new,





Using the Bev Block, flipped upside down and used in the mag well,




Finished, Will get some paint on it when it warms up a bit more.

No you are right they don't! I use the proper size punch and never had a problem. I was thinking the pins were out and work was in progress, getting things back together. My mistake. It was afternoon here in Slovakia when I posted it.

OK, this rig is now in it's final form. Took it to the Icebreaker for some open country play, and that ACSS reticle was right on the money out to 800 yards with M855.

Primary Arms 1-6x24, 5.56 ACSS reticle
Burris PEPR mount. (just learned they also send smooth ring tops along with the pic tops, went with the smoothies)
YHM Diamond free float tube.
Surefire three-prong flash suppressor

Looks fine, MM. Nice work!

Looks good to me. Can you see your front post? I can see it on my HBAR. Gonna take a cutting wheel to mine.

I can see the front post at 1X, but PEPR mount is tall enough to put the reticle center above it. At 2X the post is hardly visible, at 3X it's not visible.

The ACSS reticle is second focal plane, and is calibrated for use at 6X.



I had initially gone with an AR-Stoner 20 MOA mount from Midway. It is significantly lower than the PEPR, and the front post was in the way at low power.



On the PEPR 30mm mount, the scope centerline is 1.6" above the receiver.

With the AR-Stoner mount, it is only about 1.4" above the receiver, and with forward slope. It is a no-go for a rig with a fixed front sight base and low power optics.

I haven't measure my old Armalite mount but it blurs the Nikon I have on their right now. On my M4 build I put a YHM flip up front sight. The HBAR has a postban front sight so I'll just cut that for the time being. I'll keep track of the mounts you listed. Good info.