I've got a few M16A1 stocks that have the pinned rear sling pivots.  I'm trying to take the entire pivot unit out.

So far I've got the pinch pin out, but I can't seem the get the ball/bump unit out of the stock.  It digs into my collar and I just want to pull the sucker out.

Any tips?

It's not the sling pivot (the part where you thread your sling), it is the housing that the sling pivot is pinned into.

I just want a smooth lower stock that has no projections.

Any simple tips before I start grinding it down with a grinder?

It is held in only by the pin that goes through the stock.  I assume some gunk or corrosion is holding it in.  You should be able to twist it with the sling loop to break it loose.

I put some kroil on it and twisted it off with a pair of pliars.

Lots of gunk in there, yeech!

Thanks!