How to change AR-15 Takedown Pin?

[Bogie]

Okay - I bought one of those extended Takedown Pins at Watson's table when I was at Knob Creek... Now I finally decided to switch the pin on the rifle... I popped it open, and looked at it for a little while to try to figure out how it comes out, and durned if I can figure it out...

[George Stringer]

Bogie, I'm not an AR expert, but if I remember correctly there is a small spring and plunger located at the lower right of the barrel on the lower receiver looking at the action from the muzzle. These two parts hold the takedown pin in place. There is a little slot that runs down it's side that the plunger fits into. George

[Bill0294]

Bogie. Before you begin the job, you need a reassembly tool. Most sold are an "L" shaped rod - from $3.50 to about $8. A hole is drilled at the end of the straight end to reinsert the detent sping and detent plunger. Some folks use a clevis pin bought at a hardware store. To disassemble the factory pin, ensure weapon is unloaded. Remove upper receiver and set it aside. With the front take down pin in the open position as far as it will go, insert a punch through the small hole on the takedown pin front to rear. Push the detent down into the receiver to clear the takedown pin slot and, while holding the detent pin down, rotate your punch, also rotating the takedown pin so that a solid side of the pin is presented to the detent pin. The takedown pin is now free to pull out of the receiver. Before pulling the pin out, have some way of catching the detent and spring. When the takedown pin is clear, the detent will launch into space and you will NOT find it.

To re-install, insert the installation tool through both takedown pin receiver bossing holes from the left. Align the hole in the tool with the detent spring hole in the front face of the receiver. Using exceptional care, place the spring through the tool into the receiver hole, followed by the detent plunger, pointy side out. Using your punch, push the detent plunger into the receiver until you can rotate the installation tool, trapping the detent spring and plunger in its proper position. Using your takedown pin, align it horizontally with the receiver bossing holes from the right. The end of the takedown pin must be hard (flush) against the end of the installation tool and axially aligned. In a fast, smooth motion, push the installation tool out of the receiver with the takedown pin, taking exceptional care not to free the trapped detent spring and plunger. You may want to do this inside a clear plastic ziplock bag to recover the detent plunger if -- I should say "when" -- it flies out of the receiver. Once the takedown pin is through the right hand bossing, rotate it to the correct position, slot to rear until you hear/feel the detent engage the slot. You're done! Good luck.