My son and I would like to build a couple of AR15s.   I have been building AK47s for a while now, my first AK47 was a M70 yugo underfolder with a new virgin barrel, virgin trigger guard, virgin rear trunnion, etc.  Quite difficult.  I have since built a few other AKMs and I want to go somewhere new and different.

My son and I want to build each an AR15 with alternate calibers due to the fact that 223 is kinda expensive (more so than even 7.62x39).  I would love to build one in 5.45x39 or even 9mm.  9mm would be nice only because then I could go to my local indoor range that only allows pistol calibers.

If the cost is a lot more for alternate calibers, then I willl stick with the stock .223.

If you want to build alternate calibers, don't you realy only have to worry about the uppers?  You can use the same lower for whatever caliber you choose, correct?

We want to make this a budget oriented build if possible, heck, thats why I went with AKMs inthe first place.

Thanks...

If you are really set on something other than 5.56x45, maybe check out the AR variant section.  If you ask me, 5.56/.223 is way more versatile and effective than any handgun caliber.  Most people with handgun caliber AR's already have a 5.56 AR.  A rifle-caliber carbine (even a smaller caliber like 5.56) has a lot more energy and range than a handgun-caliber carbine with similar recoil.  
A few places like Del-Ton, J&T, etc have really cheap kits with plenty of options.  All you need to do is locate a stripped lower and have a local FFL transfer it to you.  Good luck with your build/s.

Thats why I posted.  I was just putting the 9mm out in the open but I agree that the .223 is the most versatile. The only thing that bothers me is that ammo is rather pricy these days for .223.  

Are there any 5.45x39 uppers anywhere?  I actually think I would buy 2 lowers for myself, one for .223 and the other for something alternate.

I will have to check out the variant section.  

Is putting together a variant more difficult than putting together a stock carbine?

Building out a 9mm AR is rather straight forward.  Rock River Arms of course is probably the most available resource of 9mm parts.  The various dealers on this forum have lots of Rock River 9mm parts.

ADCO (Steve)
Legal-Tranfers (Pete)
Eagle Firearms

What you'll need:
9mm Mag Well
9mm mags
9mm Carrier & Hammer
9mm Barrel
9mm Buffer