Everything is my fault, let's get that out of the way.

Pre-41F I panic submitted a handful of stamps including 2 AKs, a PAPM85 and a Wasr-10

Both are now approved and the fun part starts.

The Wasr stamp says 12" and there's no way in hell I get close to that

I was originally hoping to incorporate a venom gas block/front sight but I guess that's a no go and now I'm using the OEM parts which only take up barrel real estate and don't reduce weight out front. The gunsmith estimates I can get it to 13.8" which frustrates me.
Maybe I should have gone 14.3ish and pinned a Keymount flash hider for my Sandman S and saved $100 or so in the long run.

I know I can cancel the stamp since it's unbuilt but fuck it, I'm already this far, no turning back.

Someone tell me that a 14" SBR is still cool?

She got boxed up last night, just waiting on the arrival of my ALG trigger from @PrimaryArms and she'all ship next week.

... so you applied to build something before you knew whether or not you could build it .. ? Do I have that about right?

That said, who cares! See what you can get out of it. 13-14" might be cool? Not like SBRs are part of HPA. You're going to have to pay/wait either way. Or you could go REALLY extreme, and put a new front trunnion and barrel combo on it, to get you to 12".

lol basically; I had 41F fever. With the venom gas block/front sight it would have been 12.x"

Why can't you use the Venom gas-block/sight ?

Couldn't you just build it how you can build it, then notify the ATF in writing of a permanent change?

Buy amd length barrel from ak-builder, populate, replace barrel, headspace, taaday! not easiest or cheapest solution, but it will work. I am going to do this at some point.  Also, I think, as was said above, you can build it to what ever length, then notify atf of change in a letter...not sure you even have to notify them.

I'm not entirely sure. I need to get the smith on the phone

screw the ATF. I couldn't give a shit about that, I'm pissed it won't be as short as I anticipated, just barely shorter than saving a $200 stamp and engraving (figure $100 net cost after paying to pin and weld).

This.

You are basically creating and AK104 with a 12.5" barrel, but using the venom gasblock instead of the Russian or Bulgarian 104 combo block

What you put on your form 1 doesn't matter.

If you make a permanent change you MAY let them know in writing but you don't have to.

If your barrel is larger than .591" you would just need to have the barrel turned down to fit. If your gun smith doesn't possess a lathe then go somewhere else. Build the gun the way you want it.

Buy parts and turn it into a Krink. You already have an approved stamp so don't waste it. Krinks are my favorite AK variant. Go short.

@Mageever - what's the deal on supply for 14mm Flash hiders? And Sandman front flash caps

I'll bust out the calipers tonight

I need to touch base with the gunsmith in regards to the venom on Monday

and I just had my rear trunnion fixed on my mini draco because I was thinking who would want the parts off this thing anyway.

a 14" SBR is borderline lame on a .308, don't even bother on a 7.62x39.  

Besides, to make sure the threads are concentric anyway, you need to pull the barrel and trunnion.  See if you can get an adjustable gas block on it, based on my experience with a SDN-6, you will want one.

It's cool bro. I like my 14.5" M4.