"Slick Side" upper- no forward assist or brass deflect

[Midmichigun]

Guys,
After careful research, it appears that this upper is actually a "604" type. The factor that decides this is the raised lettering for the elevation. Technically a "601" doesn't have any lettering.... whereas a "602" is stamped or engraved. My research was from here:
Build Guide
So the question that I face, is whether to build it as a "604" or "601". I would simply grind off the elevation markings for the later.
I have yet to procure a barrel or stock set.
It appears that a "604" uses a conventional easily had charge handle. Which would save me a Nodak repo.
I have now seen photos of a 604 in service during Vietnam, which gives it a nifty historical precedence.
So whatcha guys think???

[browningautorifle]

I was actually talking about the 610 or 649 because they handle so nice. Something short and handy, not rifle length.

[Midmichigun]

BAR,
Ok... going with that Carbine concept... then we would have a GAU or GUU-5P type carbine.
I ordered an 80% Tactical Machining Lower and got it earlier this week.
Here we have beside my "604" upper:

To "upgrade" the lower, I am going to mill off part of the fence surrounding the mag release.

Here is the lower roughed out.....

The FCG is fully machined, and most of the fence is trimmed back. Next up to do is grab my dremmel and clean up the edges and smooth things out.

Here is the "mockup" of the GUU using an M4 barrel. According to my research, this was common on rebuilt models. The stock as a UTG 4 position model. I snagged the handguards for dirt cheap a number of years ago. The blue is there just to jack off purists! I don't know if I have a charge handle to complete my build.... but here it is:

[browningautorifle]

That's almost exactly what I was talking about. The only thing I'd do differently would be a light weight barrel to keep it light. But that one's probably a fast twist so in these times it might be better anyway. Heavy bullets are probably easy to get around you and it can also shoot whatever comes to hand.

[Midmichigun]

This photo is a good overall of the build. I have ground and milled down the fence around the mag eject. Some minutes behind a dremel gave me this:


Nice closeup shot of the area. While this looks odd, photos confirm that the aluminum is contoured in this manner:


Next up to do is mill around where the buttstock screws into the lower. While this does weaken the rifle, technically this is "correct".
I still need to strip the upper to get it cleaned. It is rather nasty.

BAR,
If I had access to a pencil thin barrel as issued, I would use it. However, I have not found one "cheap" enough... and simply had the M4 barrel handy (and it is correct for late models). But I do wonder what it would be like with a lightweight barrel!

[browningautorifle]

I often thought about turning an M4 barrel down to the light weight size, but I think the M4 profile is sexy so I just left it myself. We have ours registered anyway so the SBR thing you have to deal with is a moot point. I went a bit shorter.