"Hello, my name is Jeremiah, and I've never built my own gun."
Now that it's out in the open, let me tell you how tough it is to decide what to build. A custom 1911? Well, I have a buddy who has built many and could help me to make one heck of a shooter. A 1000 yd bench .308 out of my 700 VLS? Too easy. Besides, once I adjust the trigger I'll have a 500 yd tack driver. A dbl action ICORE competition gun out of my 4" GP100? VERY challenging I would say. It would be awesome and I probably will still do it one day.
So, I've got a bushmaster .223. Love it! I'm going to armorer school soon for the Army so I'll have plenty of time to practice working on other AR's. I'm already pretty familiar with the AR platform. Hmm, .308 AR it is!
Now for the specifics. I'm thinking I want to do it all myself. If I have to buy new/specific tools then I will. If it takes me 6 months, thats fine. As far as what I'm wanting the gun for, I would say mid range hunting and target shooting. Hold on a sec, does anyone really need to explain why they want a gun?!? Heck no! I want it because I do and its my god given 2nd amendment right to "Bare Arms." So stop asking!

Here is what I'm thinking so far.
Stripped lower - install custom trigger
Quality stock
18 to 20 inch barrell
Long floating hand guards
Flat top upper for red dot - ACOG or similar
Quality bolt
What ever other small parts I may need
It looks like I will have somewhere around a grand in it minus the sights. Doesn't seem to be many .308 lowers to choose from. Lots of places have them listed as being on back order or out of stock.
Hopefully I can start buying parts in October.
