Sig Sauer 522 Front QD Push Button Sling Swivel

Attaching a front sling mount to the Sig 522 has been causing quite a bit of confusion for some time now.  This blog entry is to answer some questions and give at least one solution.  I wanted a swivel QD (quick detach) mount to accommodate a 1.25" sling width. 

First off, some technical info:

• The faux gas block on the 522 is outfitted with 10-32 threaded holes on both sides.
• The depth of these holes is .4575 inches deep.

Source:

DoubleStar UMPB A202 QD Push Button Sling Swivel & Mount 

Price: $15.99

10-32 QD Mount Only

Price: $9.99

The faux gas block as the rifle comes from the factory.

A closer view of the faux gas block.

Ace model UMPB-A202 package contents.


Ace model UMPB-A202 comes complete with the QD for 1.25 inch strap, a 10-32 flat head screw, and a 10-32 nut.

The threaded holes are .4575 inches deep and, fortunately, the flat head screw is short enough not to bottom out in the hole.

Insert the screw through the bottom of the QD mount, add some blue loctite...

... and screw it down tight into the faux gas block threaded hole.

Snapping in the QD swivel, there is full 360º rotation and the mechanism engages and releases cleanly.  The nut was not used.

With the 1.25 inch strap attached to the swivel.

Side view of swivel.

Side view of rifle with swivel and strap attached.

1.25 inch strap.

Top view of QD swivel and strap installed.

Hope you found this information helpful.
Mike