[kraigwy]

I have a hard plastic one (forgot the Brand, its out in the shop). It goes under the carrying handle and pops down on the ridge above the action.

It works great. You never know its there when you're shooting (assuming you're right handed because it hangs on the right side of the rifle).

It doesn't interfere with your positions (I shoot NRA/CMP positions, Standing, and using the sling in sitting and prone).

I've had this since the mid 80s and have never had empty brass causing a jam.

When practicing I normally empty it between strings (meaning 10-20 rounds) but it will hold 50+. I don't know the + part, but I have shot a full 50 round HP course (10 standing 10 setting rapid, 10 prone rapid, 20 slow fire) without emptying it.

I don't know about the bag types, haven't used them but mine works great. Don't know if I would want a bag of brass swinging around under the rifle while I'm shooting, mine is ridged.

Later I'll get a picture of it hanging on the rifle.

Sure is nice when shooting in the snow.

I use it on both my SP1 (M16a1 style) and my White Oak Upper (M16a2 style).

Don't know how it would work on a flat top, I don't have one.