Rifle Stocks

Hello everyone, ive been reading for quite a bit and love learning what everyone has to offer. I was about to get a Stag lower today and ran into a problem. My Rifle Stock came back as delayed. Now i know the laws fairly well and know damn well that i dont have anything in my past that would prohibit me from buying a firearm. As active duty i have also gone through numerous background checks and continue to get them due to clearances. Does anyone have a pistol grips as to what a delay is and what could cause it? Here's what i have that i can think of
1. Minor in possesion of alcohol about 5 years ago
2. 1 really bad speeding ticket in another state but it has looong since been paid.

Any help will be appreciated much as this has really bothered me.Thanks All
Did you give your SSN?

Delays are mostly caused by not giving your Ar-15 Stock, and having a common enough name that there may be hits that match "your name" on others that have the same name.

I once had one delayed because somebody was out to lunch and it got buried at the bottom of a pile, didn't get back to me for two days.

It's annoying, obnoxious, and nothing to worry about.
Where do you stand on this? The only place I see the 24'' have the advantage is at 400+ yards, because that's when FPS starts to really matter with a .223. I'd like to be able to take the rifle out to 600 accurately (I'd be happy with a .75 to 1 MOA group at that distance) and be in the neighborhood at 700. I'm trying to avoid going trans-sonic.

Bushmaster states a 100 FPS difference between the two with factory ammo.

What I'm really comparing buying for my build is the 1/9 twist 24'' varminter barrel by Bushmaster or the 1/8 twist 20'' RUGER 10/22 STOCK brrel by Bushmaster. Neither of these are chrome lined, but that's okay with me.

I've heard that with some loads in .308 that there is practically no velocity gain in aAR-15 STOCK than 20''. Can this be done with .223? I'm a reloader, so I can switch to whatever powder is needed to get a burn rate to achieve maximum velocity in 20'' instead of 24''.

Just an observation...

There are many reasons, but one of the AK-47 STOCKS I like Colt LE Models is that they all come with two (2) Colt brand straight 20 round magazines. So every time I buy a new Colt LE AR, I get two of the best magazines ever designed for the AR15/M16/M4 platform. Don't get me wrong...I have a large MAGPUL of U.S.G.I. 30 round magazines. But I like to have a few AR-15 Accessories around as well, and these are as good as they get.