A2/A4 stock spacers - are they all about the same?

[Buncheong]

I bought a Colt OEM A4 stock from Brownell’s awhile back and want to use it for a 20” rifle build. But these don’t come with the top screw in the butt stock or the butt cap spacer.

The only butt cap spacer I can find available is made by someone called Luth-ar LLC. Are these good to go?

I would buy Colt for a Colt stock but I can’t find any.

Thanks for any user feedback...

[titsonritz]

http://www.specializedarmament.com/%E2%80%94-buttstock-fixed-%C2%B7-rifle/spacer-buttcap-nylon/

[556Cliff]

Specialized Armamaent in the link above and Brownells here. > https://www.brownells.com/rifle-parts/receiver-parts/buffer-tube-parts/buffer-tube-hardware/ar-15-buttcap-spacer-prod22847.aspx

Here's a good source for the top screw. > https://yhm.net/buttcap-screw-with-nylock.html Brownells has Colt stock screws but they cost quite a bit more and it's hit or miss if you get one with the drain hole.

[titsonritz]

Here's a good source for the top screw. > https://yhm.net/buttcap-screw-with-nylock.html Brownells has Colt stock screws but they cost quite a bit more and it's hit or miss if you get one with the drain hole.

I little off topic, but the manual says not to re-use these screws and that they should be replaced when removed. Do you (or anyone) know why that is?

[556Cliff]

I little off topic, but the manual says not to re-use these screws and that they should be replaced when removed. Do you (or anyone) know why that is?

It's due to the Nylock patch. Every installation degrades it since it just causes a friction fit. YHM also sells the same screw without the Nylock patch and you can just use your own threadlocker. > https://yhm.net/buttcap-screw-without-nylock.html

[lysander]

I little off topic, but the manual says not to re-use these screws and that they should be replaced when removed. Do you (or anyone) know why that is?
Same reason you aren't supposed to reuse any self-locking screw.

[titsonritz]

It's due to the Nylock patch. Every installation degrades it since it just causes a friction fit. YHM also sells the same screw without the Nylock patch and you can just use your own threadlocker. > https://yhm.net/buttcap-screw-without-nylock.html


Same reason you aren't supposed to reuse any self-locking screw.

Thanks for info.

[Buncheong]

A follow-up question:

Do milspec/issue rifles use the nylon spacer, now? For some reason I thought they used aluminum...

[556Cliff]

A follow-up question:

Do milspec/issue rifles use the nylon spacer, now? For some reason I thought they used aluminum...

Unfortunately I don't have an answer on that... I think they used to use aluminum spacers, but that's just a guess. It's also been impossible to find out if newer military issued M16A4s with rifle stocks have aluminum or plastic trap doors.

[lysander]

The buttcap spacer has been plastic since 1988.

[Buncheong]

The buttcap spacer has been plastic since 1988.

Thanks much for the info! :)