AR15 rear pivot pin screw

**DavidH** · September 19th, 2022, 04:12 PM

Originally Posted by bogey1

THIS^^^^ I tap mine and have been using screws from my rc planes and cars but I'm all out of them.
4-40 set screw.. Never knew the size.. THANKS!

I have a bunch to, if you need. I*ll drop in an envelope & mail it to you if you*d like & don*t feel like buying a pack. Just hit me up.

**GOYABEAN** · September 19th, 2022, 04:42 PM

Originally Posted by DavidH

It*s not a 4-40 set screw for the bolt catch. It*s a 308 bolt catch pin. These are called the *Enhanced* lower features. A 4-40 set screw for the Pivot pin detent & spring, threaded for the 308 Bolt Catch pin, (as I outlined) & a nylon tipped 1/4-28 set screw behind the grip screw that takes the play out of the upper & lower. Eliminate the well known *Rattle* between Upper/Lower. I*m actually switching to a new brand of 80% 7075-T6 Billet Lowers for the AR*s I build & these new ones have the enhanced features.

BTW: anyone can do these *enhancements* on their own.

Yes some might not use 4-40 set screws I've used them on a few polymer lowers
Bolt catch mods

**DavidH** · September 19th, 2022, 06:09 PM

I just meant it wasn*t the same set screw that is used for the detent & spring. It*s an actual threaded pin. One can make it, sure.. but it*s a specific part called a *308 Bolt Catch Pin*. They cost like $2-$5. It*s something I would buy. I*m big on small parts. The pins & springs and such. I don*t buy LPK*s. They use most stamp steel & fast parts. And typically cheap springs. I use very quality pins & springs. All machined. Some steel, a few 7075 billet parts & even Titanium, like the TakeDown/Pivot pins. Using very high precision small parts are one reason my builds are every bit the rifles that the Top Shelf picks are. If given a choice between one of my built AR*s or a $2800+ Knights Armament, I*ll take my AR in a heartbeat. And I build them for less than HALF of the Too Shelf*s.

**bogey1** · September 19th, 2022, 06:41 PM

Originally Posted by DavidH

I have a bunch to, if you need. I*ll drop in an envelope & mail it to you if you*d like & don*t feel like buying a pack. Just hit me up.

I bought ten, but if you have some you dont need I'll take them. Always losing them.
Just let me know what I owe you. Thanks.

**SteveWag** · September 19th, 2022, 07:34 PM

The OP asked an impossible-to-answer question. First, he referred to a "AR-15", this means a GENUINE Colt product. Second he asked about a "rear" "pivot pin", such a thing does not exist. Nothing can pivot about the rear take-down pin of an AR-15 or a AR Clone. Now, the "pivot" (from the cleaning instructions), take-down pin of the AR-15 did have a screw.
Link to Photo:

https://www.gswagner.com/ar-15%20Pivot%20pin.PNG

A few of the stripped lowers for clones I've received recently have had the rear take-down pin detent spring retained by a not-supplied 4-40 grub screw. Some AeroPrecision and all ATI for example.
I think the posters should consider their word more carefully!

Steve

**Walleye Hunter** · September 19th, 2022, 08:06 PM

Originally Posted by SteveWag

The OP asked an impossible-to-answer question. First, he referred to a "AR-15", this means a GENUINE Colt product. Second he asked about a "rear" "pivot pin", such a thing does not exist. Nothing can pivot about the rear take-down pin of an AR-15 or a AR Clone. Now, the "pivot" (from the cleaning instructions), take-down pin of the AR-15 did have a screw.
Link to Photo:

https://www.gswagner.com/ar-15%20Pivot%20pin.PNG

A few of the stripped lowers for clones I've received recently have had the rear take-down pin detent spring retained by a not-supplied 4-40 grub screw. Some AeroPrecision and all ATI for example.
I think the posters should consider their word more carefully!

Steve

I'm more of an H&K guy but wouldn't a real Armalite 15, be made by...well..Armalite?

**DavidH** · September 19th, 2022, 08:31 PM

Originally Posted by SteveWag

The OP asked an impossible-to-answer question. First, he referred to a "AR-15", this means a GENUINE Colt product. Second he asked about a "rear" "pivot pin", such a thing does not exist. Nothing can pivot about the rear take-down pin of an AR-15 or a AR Clone. Now, the "pivot" (from the cleaning instructions), take-down pin of the AR-15 did have a screw.
Link to Photo:

https://www.gswagner.com/ar-15%20Pivot%20pin.PNG

A few of the stripped lowers for clones I've received recently have had the rear take-down pin detent spring retained by a not-supplied 4-40 grub screw. Some AeroPrecision and all ATI for example.
I think the posters should consider their word more carefully!

Steve

Huh??

https://www.youtube.com/watch?v=L5A8vQx5pCU

**SteveWag** · September 19th, 2022, 08:47 PM

An Armalite 15 would be an "Armalite 15". "AR-15" is/was a trademark of Colts Patent Firearms or whatever it has now become.
Steve

**DavidH** · September 19th, 2022, 10:20 PM

Originally Posted by SteveWag

An Armalite 15 would be an "Armalite 15". "AR-15" is/was a trademark of Colts Patent Firearms or whatever it has now become.
Steve

**bogey1** · September 20th, 2022, 06:50 PM

Originally Posted by SteveWag

The OP asked an impossible-to-answer question. First, he referred to a "AR-15", this means a GENUINE Colt product. Second he asked about a "rear" "pivot pin", such a thing does not exist. Nothing can pivot about the rear take-down pin of an AR-15 or a AR Clone. Now, the "pivot" (from the cleaning instructions), take-down pin of the AR-15 did have a screw.
Link to Photo:

https://www.gswagner.com/ar-15%20Pivot%20pin.PNG

A few of the stripped lowers for clones I've received recently have had the rear take-down pin detent spring retained by a not-supplied 4-40 grub screw. Some AeroPrecision and all ATI for example.
I think the posters should consider their word more carefully!

Steve

Everyone knew what I was talking about but you.