[Tech knight]

I now have plenty of 5.45x39 ammo. What parts do I need?

If I order a Spike's AR15 mid length in 5.56, what other parts will I need to shoot 5.45?

I see Spike's sells a part for shooting 5.45. Is that all I need or do I need a different barrel as well?


On a related note I saw you can switch a single part and shoot .22lr out of it in a youtube video. Is this true?

[Bushflyr]

You need a whole new upper. And mags.

You'll need a 5.45 barrel, and a 5.45 bolt. All other parts are the same as the 5.56
You can run dedicated 5.45 mags, or try your luck using 5.56 mags.

With the 5.56 assembly, you can remove teh bolt carrier group and replace it with a 22lr conversion.

[boomhower]

Easiest way is to just get a 5.45 upper. S&W is a popular choice as well for them.