Hey guys, been reading SO much information from everyone, so thanks up front for all of that...

I am starting my pistol build and have parts on their way, but my first question is this:  how common of a problem is the upper/lower not fitting correctly?  I have a DD stripped upper on the way, and was planning to get a stripped lower from the local gun shop. I was planning on taking the upper in to see how close it is ( I am guessing  it's not the same as have it pinned in?).  Local shop won't have anything in until later in the week, they sold the Anderson lowers that they had end of last week, and I'm guessing they're getting the same in.  Guy tried to upsell me to POF, but that's talking quite a bit of difference.

 As far as other certainties for this build:

 DD 11.5" barrel
 KX5
 PSA LPK
 DD BCG
 Ace pistol buffer tube assy
 YHM low-pro gas block
 Probably a Midwest Industries SS GEN 2 12" handguard


 It's going to be my first build, so any other insight/advice is much appreciated.

 Thanks - BS

0%.

Everything fits everything.

However... I can tell that matched sets tend to fit a little more sung.
Just pick what you like and it will fit together with the front and rear take down pin easy.

AR's seem to be overwhelmingly plug and play.  I just built my first one throughout the past couple months or so.  Gotta love it.  BTW, you could be sliding down a slippery slope know round these parts as BRD....

Thanks for the info!

Oh, believe me, it's already gotten quite the foot-hold, haha.  This is my first build, had thought about getting complete upper, but opted to get my hands dirty and put what I wanted on there.

 -BS

Exactly the same odds as fitment on AR rifle. Most combos fit fine, sometimes some are a bit tight or loose.

- OS