Project Featherweight

**LonghunterCO** · 02-23-10, 16:27

Originally Posted by Al U. 5811

gotM4,

Who, other than Sun Devil, makes a flat top upper w/o an FA? I'm not sure if Sun Devil has feed ramps in their non-FA upper.

Assuming that you are looking for a light weight build I would stay from the milled upper like Sun Devil. I would look for a Rock River 9mm upper ( I think that ADCO has had them in stock yesterday).

**TwoSqueeze** · 02-24-10, 12:31

Originally Posted by Al U. 5811

gotM4,

Who, other than Sun Devil, makes a flat top upper w/o an FA? I'm not sure if Sun Devil has feed ramps in their non-FA upper.

I know that VLTOR makes a billet upper w/o FA. I think that Black Rain Ordenance does as well.

-TS

**rob_s** · 02-24-10, 12:33

Originally Posted by LonghunterCO

I would look for a Rock River 9mm upper ( I think that ADCO has had them in stock yesterday).

you're going to need a hole for that pesky gas tube.

**Al U. 5811** · 02-24-10, 20:52

I would think that a billit upper would defeat the purpose of light weight.

**Robb Jensen** · 02-24-10, 20:52

Originally Posted by Al U. 5811

I would think that a billit upper would defeat the purpose of light weight.

Yes they are 1oz heavier, sometimes more vs. a standard forged upper receiver.

**f.2** · 02-24-10, 21:20

Originally Posted by gotm4

...Components:

RRA 1x8 16" midlength barrel cut to 14.5" and turned down to .565" barrel profile...

What is the decimel inch profile for a pencil bbl? (i.e. .565")

I want to have my BCM 16" middy turned down by Adco and cut down for weight like your build. Would 14.5" or 14.7" be optimal for reliability?

**Robb Jensen** · 02-24-10, 21:31

Originally Posted by f.2

What is the decimel inch profile for a pencil bbl? (i.e. .565")

I want to have my BCM 16" middy turned down by Adco and cut down for weight like your build. Would 14.5" or 14.7" be optimal for reliability?

I'm not sure what BCM is using for a gas port, Project Featherweight is a RRA stainless 1x8 midlength 16" which was cut to 14.5", the gas port wasn't touched.

Most 'pencil barrels' are .625" (5/8"). Project Featherweight is .565" I believe .555" is about the lightest one should turn it to. The gas block seat was left at .750" so that a custom gas block wasn't needed.

Dano5326 · 02-24-10, 22:49

-do the RRA 9m upper have a hole for the gas tube?

-can you take off the shell deflector deal thing on those 9mm uppers and allow for a full size ejection port?

-does someone else make a 556 picatinny upper sans forward assist?

Thoughts of a uber light upper, maybe put grooves in the bolt carrier like the scandinavian G-3 varients to allow a thumb/finger forward assist.