STBA Replacement LEFT BUSHING ONLY for Tactical Innovations' STBA AR15 receiver pins sets.
If you have a receiver with STBA busings installed and lost one of the LEFT side bushings, these replacement bushings will get you fixed up. These replacement LEFT side STBA BUSHINGS will only work with STBA pins and will not work with GI receivers that have not been drilled and threaded for the STBA bushings.
Pins are shipped each. If you order one, you will get one bushing. Two bushings for each side of the receiver are required for each receiver.
For a complete STBA retrofit on a receiver, you should use the
00172 - STBA KIT
00174 - STBA INSTALLATION KIT.
For installation of the STBA bushings, all you would have to do is accurately drill the existing .154 holes on the same center point using the #1 drill bit. Its important to make sure that you don't wobble or similar and make the holes oversize. Then with a hand tap and some tap oil, use the 1/4-40 tap to carefully hand tap the holes.
Next you will want to thoroughly clean the holes with acetone or similar to remove all oil and residue. Then blow dry and apply some red locktite and using the installation tool or allen wrench as appropriate, screw the bushing into the threaded holes being very careful not to cross thread them. We don't have a torque spec other than tight but not to the point that you damage the threads, the bushing or the tool.
the locktite to set before use. When you install the hammer and trigger pins,
they may be tight in the bushings and that's good. However, you have to
ensure that the pin will allow the hammer to freely rotate. You can do
this by putting the pin through the hammer before you install both in the
receiver and make sure the hammer rotates freely. If the hammer binds
on the pin, something has to give and as a fail safe, the right bushing
will unscrew from the receiver. Under normal use with a correctly sized
and lubricated hammer, it will work as intended and not be an issue.
The pins are captured in the receiver by the spring identically to a GI