Which would be cheapest route?

[falfan]

Looking into builing a 300w, but am not sure which way to go, I plan on shooting subsonic.
I can't decide to go with an AR upper or build on a savage 223 that I have. I know some of you have built on a savage action, have you had problems feeding or extracting? I have a FP10 in 223 with blind box mag.

of course I love the ar's, but not sure I want to play around with getting it to cycle etc.
the barrel length on either of the guns will need to be at least 16" 's .