16.5" Rifle Gas Lightweight ... 77.1 oz (4 lbs 13.1 oz)

[vicious_cb]

I picked up some v7 goodies and ordered a K grip. Trying to crack sub-70 oz. I'll stop after that, I can't afford one of those boomfab bcg.

You may get better function if you use an expansion chamber type break which should give you a few more inches of equivalent barrel in dwell time.

[Moonlight Again]

I picked up some v7 goodies and ordered a K grip. Trying to crack sub-70 oz. I'll stop after that, I can't afford one of those boomfab bcg.

. . . I can quit any time I want to . . . .

[frsteve]

You may get better function if you use an expansion chamber type break which should give you a few more inches of equivalent barrel in dwell time.

Thanks! But I don't have any issues with dwell time. Everything is cycling nice and seem to have an "ideal" ejection trajectory.

That barrel is available for $150-ish nowadays!!!

[frsteve]

Quick Update ... not much time, but i replaced a bunch of parts with v7 stuff and then tweak a few other items.

I cried when I looked at the scale and my personal goal was reached ... sub-70 ounce.

[Sasahara]

Surprised I missed this thread the first time around. Congratulations on reaching your goal! I am not huge into the super-lightweight builds but it is hard to not admire the amount of research that went into this build. It really does look good! Is that a thread protector that you have on there now instead of a MD?

[SpankMonkey]

I've been following this since you posted your build list. Nice rifle OP. How is the new gas block working? also what rail did you use on the end of the FF to get the buis to line up with the rear?

[frsteve]

@spankmonkey - The gas block is working great. I found that I had to nearly open up the adjustable gas block to full open (2 clicks away), to get the gun to cycle reliably. So i figure, two clicks more gas isn't much of a problem and I didn't really notice any recoil difference. With rifle gas and lightweight internals, the gun is super soft. My Philtrum (new word I just learned - the area above the lip and below the nose) rests against the charging handle and it doesn't bite back.

That FF guard is the same AP custom, but I had rotate it 180 degrees, drill a new mounting hole, epoxied it (to protect it from fraying) and then installed the mounting screw back on to secure it to the trunion.

For the front mount of the MBUS, i simply took the 2" poly picatinny rail section and then used aluminum screws and nuts to secure it. After initially doing that, i did not like the way the nut would bite into the handguard and it didn't make as much surface contact area. I then had a friend bend an aluminum piece of scrap into the contour of the handguard. Now the screws can push against the interior plate, get better contact and better secure the front site.

It seems to hold zero pretty well, but I haven't dropped or thrown my rifle around that much. I have a carbine class coming next month and we'll see how it does there.

@sasahara - yes, that's a thread protector. I found that with better technique, it was easily controllable since the rifle shoots so soft now. I may stick the RMC mini-comp back on later, but for now, it seems ok. I really liked my PWS FSC556 I had on my other setups and may try that on it later ... I wonder if it would push it down too much. Not sure.