MONOLITHIC UPPER

[Stickman]

I want a monolithic upper rifle. I like the look and being able to mount an optic anywhere. Which one do you have and why?
Spider

I've been very happy with the various VIS that I own, no complaints at all. I've got plenty of upper receiver groups, so I have no need to switch out barrels (I have more than one VIS also).

[Stickman]

The Mega Monolithic upper that I have is a preproduction model, but its nicely machined. Since this is close, but not the actual production model, I have to reserve "actual use" comments to the other who own them.

Here are a few pictures to give you a rough idea what it looks like.

[Stickman]

[payj]

[mark5pt56]

Out of curiousity-

This applies of course if the block is covered.

If pinning a block on the VIS, is this done before torqing the barrel nut? (install the nut, pin the block, add gas tube and slide in place)

How do you pin the block on the Mega?

And what keeps either one from rotating?

Mark

[ArmedSuspect]

i went MRP and couldn't be happier. the barrel change only takes me two minutes with a TQ wrench and i'm done.

as for the barrel options, i'm fine with building off of LMT barrels. there isn't much more in barrel options that i would need. the only thing i can see adding is a switchblock and a clamp on for a middie would work just fine. now that you can use ANY AR15 barrel with a minor mod it's a complete WIN.

my current barrel of choice is a 12.5" DI, dimpled...

[onado2000]

I went with the MRP also. Dont forget with the LMT MRP you have the ability to change from piston to DI system. Mark5, that is an damn nice kit you have there !

[wild_wild_wes]

The Mega looks a lot heavier than the VIS.

[ALCOAR]

i went MRP and couldn't be happier. the barrel change only takes me two minutes with a TQ wrench and i'm done.

as for the barrel options, i'm fine with building off of LMT barrels. there isn't much more in barrel options that i would need. the only thing i can see adding is a switchblock and a clamp on for a middie would work just fine. now that you can use ANY AR15 barrel with a minor mod it's a complete WIN.

my current barrel of choice is a 12.5" DI, dimpled...

This is such a damn hot rod, Armed worked the MRP to perfection and his results on the above build are unmatched and having the ability given your depth of knowledge and time on the MRP system is sufficient, one can build an AR to a spec that is inconceivable to non mrp owners as its tough to grasp the whole concept of.."the sky is limit" on these. Hundreds of guns in one

[Southern_Partisan]

How do you pin the block on the Mega?

And what keeps either one from rotating?

Mark

You can't pin a gas block on the Mega. You have to first torque down the barrel nut, and then slide a set screw-type gas block into place and tighten the set screws through the elongated hole machined in the underside of the quad-rail. You have to assemble in this order because the barrel nut wrench will not fit over the gas block. Pinning a gas block would not be a problem with the VIS because the lower portion of the rail is removable as noted earlier.

I had sent my components to Adco to see if they could pin my Vltor low-profile gas block. They did a trial fit and found that they could not properly access the gas block through the holes in the rail for pinning (the angle wasn't right and they couldn't drive a pin straight in). The BCM BFH 16" mid-length barrel I used for my build came with one dimple, so I had them install a second dimple. I was advised by rob_s that Rocksett is less prone to degradation due to heat than Loctite, so that is what I had them apply to the set screws to attach the low-pro.