How to install an ambi safety on an AR180B Claven2 style ;)

[Claven2]

OK, apparently Armalite once made ambi safeties for the AR180B. Good luck finding one - I looked and could not even locate a picture of a factory ambi safety, let alone one available for purchase.

I'm a lefty, so of course my OCD dictated I make one

I started by ordering a standard safety selector from Wolverine Supplies up here in Canada as a spare part. I retained the original safety from the rifle in case I or the rifle's next owner wants to go back.

AR180B safety on the left, AR15 safety on the right. This is where I give a shout-out to CGNer sigboy who was awesome enough to send me a spare used AR15 selector which made this little project possible.



Now for those who don't know, you can't even cut these with a file. AR safeties/selectors are glass hard. To even think about modding one you have to anneal it. Heat it up with a map gas or OA torch until red hot and then let air cool. It will now machine, though it will still be harder then low carbon steel - they are probably cast from 4140 harden-able steel alloy or similar.

I cut the tail off the AR15 safety leaving enough meat to grab in a collet (Hardinge 3C collets ROCK!) on the lathe to cut a clearance hole and a 0.190" diameter countersink using an end-mill held in a Jacobs tailstock chuck.



I made an appropriately sized 4-40NC screw out of a larger screw on the lathe, though in truth if I had felt like leaving the house this could have been bought and the head turned to precisely fit the countersink. I also annealed the spare AR180 selector and cut a slot in the tip and drilled and threaded a 4-40NC hole into the centre on my knee mill. I also milled the back of the AR15 selector down flush to the circular flat skirt but left a slightly oversized tongue which I shaped with small files to precisely align and fit the tongue to the slot on the modified AR180B selector.



Mocked up:



Finally, because the AR15 selector skirt is slightly too large and interferes with the rectangular receiver protrusion where "FIRE" is written (not sure what that hump for???), I filed the pointing arrow off the modded AR15 selector lever and used the mill to cut a slight circular relief into the radius of that "hump". I then filed an indicator line on the skirt to replace the pointer. Finally, I re-hardened the parts (heat to red hot, drop in cold water) and re-parkerized them.




I think it turned out well, though the screw I made didn't take the park as well as the selector bits. A minor inconvenience I can live with.

Works like a charm

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[Chuckindenver]

nicely done..almost makes me want to keep my 180B...

[Claven2]

Since I permanently installed a steel parkerized nightforce M1913 rail on the top of mine, it's become a permanent addition to the black rifle stable. I also installed an old 180 cocking lever on it, though I might make an AK style handle for the bolt and run that for a while to see if I like it or not.

[gsthreeeight]

Claven 2,

I had the same problem: a Southpaw with an AR180B, and no available ambi safety.

Solved the problem a bit differently. I ordered the standard ambi AR15 safety from Armalite in order to obtain the right side lever. Took the AR180B safety and the right side lever to a local machine shop and had them mill a slot in the right end of the 180B safety shaft then drill and tap to accept the attachment screw provided with the AR15 ambi safety.

The machinist did comment that that was a seriously hard bit of metal and that he broke a couple of drills in the effort!


Regards
GS38