So here I am .... again.  I've got an unbuilt AR lower, enough parts to finish the lower and a spare BCG.

I've already got....several....other AR's, all 5.56/.223.

What can I do that's different and interesting with a regular AR lower?  Are there any options for 9mm or 7.62x39 with a regular lower?

You could go with a 7.62x39 build. It works well but not quite as reliable as my AK with some really hard primer surplus ammo.

.458 Socom, .50 Beowulf, .300 AAC, 6.5 Grendel ???

2 minutes ago, PK90 said:

.458 Socom, .50 Beowulf, .300 AAC, 6.5 Grendel ???

Yeah, I'm trying to practice caliber discipline and not branch out into calibers I'm not already using.

.300 is interesting though...

What about keeping with 5.56, and building a different configuration? 

I don’t know what you have already, but everyone needs a 20” rifle in the mix. I prefer an A4, or A2, but there is something lovely about the simplicity of an A1....

Oh crap, now I want an A1...

How about one, regardless of caliber, that you will keep in your trunk so that when the shit finally comes down (as it will soon, I predict) you have a way to get where you are going safely.

Loaded on stripper clips and kept in your trunk in a waterproof container, a mix of 62gr penetrator and 55gr soft tip .223 would be my personal recommendation.

I vote 7.62x39  AR  Its my new favorite ar to shoot. 

It really depends on what you want and what type of shooting you are going to do.

Want something different yet avail?  7.62x39.

Something a bit better ballistically?  224 valk.  

new fads?  350 Legend, 450 Bushmaster

Or build a dedicated 22lr upper gun for training. 

Do you have to build something?

surprised a 5.45x39 wasn't mentioned...

 

 

Off a standard AR lower....

223 Valk if you can afford a new barrel every 2000 rds and dont mind single loading.

7.62x39 for ammo economy and availability.

243 WSSM. Expensive but kicks ass in the AR platform

6.5 Gren for ballistics, and saying Grendel is fun.

338 Lapua because its sexy, even if it is single feed.  Long reach.

9mm is great for SBR

458 SOCOM for making big holes in stuff inside 200yds

50 BMG for making bigger holes in stuff out to 1500yds

 

 

.22 dedicated 

What kind of ARs do you have now? That will help us fill your gap

7.62x39m Is a must for every AR collector. Its fun to shoot ammo is cheep. I use Wolf Steel cased. Out of 500ish rounds i only had 2 dudes where i would repeatedly load it in the chamber and fire it leaving the marks and wouldnt fire. other then that. it runs great. :-)

@DirtyDigz

https://www.thetruthaboutguns.com/2019/04/daniel-zimmerman/cmmgs-9-arc-magazine-convert-an-ar15-to-shoot-9mm/

9 made easy