204 Ruger lower question

[tmajors]

Found an AR lower for $99 listed for 204 Rugar. Can this be used as a base for a .223 upper or are they different? I thought with AR's it was the upper that determined caliber, not the lower.

 

[Auburn1992]

The upper (as of my knowledge) is infact what determines the caliber. The .204 and .223 use the same bolt face, mags, and therefore should be able to use the same lowers. I know that you can get an upper in .204 for your .223 ar, so I am pretty sure you can get it the other way around as well.

The only lowers determined by caliber are those of short action catridges like the .243, .260, 7mm-08, and .308. These use a much larger mag well as opposed to the .223 cartridge.

 

[gvnwst]

yeah, it is just like a lower marked .223 rem can use many other calibers, if it is a AR lower that takes standard mags, it should be just the same as any other.

 

[tmajors]

Great! Guess I just bought my first AR lower to build my first AR with ...unless someone says differently