Receiver Extension Indexing Channel and End Plate Tab (Thread damage on installation)

[Ned Christiansen]

Agreed, it's common, a weak area in the design as far as assembling it goes. Doesn't seem to be an issue once it's together, even when the RE's keyway is completely buggered up.

[Purkeypilot]

Thanks for all of the responses all. I appreciate it. The tools and components used were:

BCM Receiver Extension
BCM Receiver End Plate
BCM Castle Nut
Hammerhead Rifle Tool
Squirrel Daddy Delrin Lower Receiver Vice Block
Craftsman ft/lb torque wrench
Aeroshell 33MS Grease

I think Renegade has gotten very lucky for the last decade. I definitely understand how to perform the procedure as well as how to use the tools I use. My dumb ass just didn't think to hold the RE in place...I figured the tab/channel would do that. I fully comprehend now that 40 ft/lbs of rotational force is enough for 7075 aluminum to be defeated by steel. I'm embarrassed honestly. I just wanted to make sure that it's good to go when assembled and didn't require the tab/channel to remain straight after the fact. It makes sense that it's more about the tension between the Castle Nut and End Plate.

On a side note; I got my MOACKs Plain a few weeks ago Ned. It's awesome! Thanks again

[Ned Christiansen]

Cool on the MOACKS, I remember the name.

This is an area that I've buggered a few in my time (and I always confess this in classes when we get to this area :-) ). You have a keyway cut into relatively soft aluminum, and then half the aluminum keyway's side area is removed via the threads, then a key to fit into the keyway that is steel, but A) not very long (ever notice how Woodruff keys are like 4X longer than wide?), and B) very likely the key's side area is reduced by the fact that it's a stamping and as happens in stampings, the steel has "rolled" a bit before the part was sheared out. The result is very, very little bearing area, key-to-keyway. No wonder it's so technique-intensive to not gnarf it up.