I have a SureFire Socom Mount (SF3P-556-AUG) for the Stey Aug.  Included in the package with the mount was a round metal bushing-type object.

It is beveled on one end and is marked with the number 70307-41.  Can someone tell me what this?  I tried googling but there's not much info on these mounts or their installation.

Thanks

I don't have one but if I had to guess I would say that it's to cover up the gap between the flash hider and the barrel where the threads start.
The AUG check nuts function the same way.

That's what you do.

Where are these available? Optics Planet says:

SureFire 3-Prong Flash Hider/Suppressor Adapter 5.56mm AUG SF3P-556-AUG has been discontinued by SureFire and is no longer available.

I got this on Gunbroker when I was trying to decided between the Aug and the Tavor.  I went with the Tavor but had already won the auction for the mount.

These are at in stock at Opticsplanet. If you look in firearms related deals thread in General subform, you can get a 10% coupon from Jesse if you send him a PM. http://www.ar15.com/forums/t_1_180/1751724_10__12__Off_Optics_Planet_Discount_Code.html

http://www.opticsplanet.com/surefire-3-prong-flash-hider-suppressor-adapter-5-56mm-aug-sf3p-556-aug.html

this thread being reposted finally motivated me to go to the garage and install the one I had purchased several months ago.

the spacer has one end that is beveled, this matches the bevel on the shoulder.

Install went pretty easy assuming you have a pair of relatively thin 19mm wrenches.  However, the Surefire manual did not correctly list the Aug thread pitch as left hand.  Fortunately after having no luck and slipping a wrench once, I decided to go upstairs to double check on the PC and found out that it is indeed LH pitch.   After that, barrel in vice, had one wrench locked against edge of work bench and gave the other one a good amount of torque and it broke loose.   Looks like loctite so some heat wouldn't have hurt.

The surefire hider doesn't look out of place on the Aug although the tulip hider did look better.

Any pics of the finished product ?