Zombie Lower Question

[Judicator]

My ZA Lower came with a grub style screw. I've never built and AR before and no diagrams I look at show this screw anywhere or ever what it does. Can someone point me in the right direction please I hate sounding like a noob.

 

[jdesro]

Some manufacturers tap the hole in the rear of the receiver where the rear detent spring goes. They do this so if you change stocks you do not not have to worry about having the spring and detent flying out on you. I assume that is what your grub screw is for.

This will show you what I'm talking about: http://www.ar15.com/mobile/topic.html?b=3&f=118&t=395777

 

[Judicator]

Nah that's not it. I'll snap a pic when I get home in about 20minutes. I just want to make sure I don't need it before I finish my build


Sent from my iPhone while my co-worker is getting electrocuted.

 

[jdesro]

Hmm - well the other possibility is, if you have a Magpul MOE type trigger guard with your kit, it is the screw that secures the guard at the front, nearest the magazine well.

 

[Judicator]

Ok a little past 20 minutes but here is the screw that came WITH my ZA lower.

Sent from my iPhone while my co-worker is getting electrocuted.

 

[Jude Thaddeus]

Ok a little past 20 minutes but here is the screw that came WITH my ZA lower.

Sent from my iPhone while my co-worker is getting electrocuted.

Don't quote me but I believe that that grub screw is to take up any "slack" between the upper and lower. It works just like a accuwedge. If the tip of that grub screw is rubber/plastic, then it is definitely for that.

Here is AWS talking about it.

http://www.northeastshooters.com/vb...bie-Annihilator-AR-15-Lower-Order-Info/page49

"We just received the UPS tracking info for the new Zombie Annihilators Uppers and Lowers!!! Our new and improved lowers now feature a nylon tipped upper tensioning screw to take up any slack that might be present for a tight fit and improved accuracy. This is a nice feature if you are using another manufactures upper, as there is always some difference in tolerances between manufactures."

 

[jdesro]

Only thing I can think of is that it does kind of look like the trigger guard screw for a Magpul trigger guard.

Rainier Arms mentions their receivers come with an upper/lower tensioning screw for a better fit between upper and lower, but never having used one I'm not sure if that's what it is or where it is supposed to go.

Other than that I have no idea.

EDIT: thehoyt beat me to it! He's most likely correct - that must be what it is.

 

[Judicator]

Thanks you two. My upper and lower fit great so I shouldn't need it. I appreciate the help!


Sent from my iPhone while my co-worker is getting electrocuted.