This weekend I had the opportunity to shoot an ar pistol. Def fun and now I want to build one,  I know it has to be under 50oz total, and I know I cant have handguards. question is since its a pistol do I still have to pin the brake to the barrel and can I now use a flash hider since its not a semi auto rifle but instead a pistol? thanks

You cannot have a threaded muzzle (ie Unpinned) or a flash-hider (pinned or not)

As the owner of a couple of jersey-legal AR pistols, I say to you:
Good luck making one that makes weight and passes the evil feature test.

(It's gonna take a light weight (polymer or carbon-15) upper and lower along with a lightweight short (~7") barrel)

thank you.  the one I shot was a new frontier polymer, and a slick side upper polymer also I believe. he said it had polymer lpk and a lightened bcg.  I saw voodoo has a 7.5'' barrel that is 0.82lbs. do you happen to have specs on what you used on your builds?

The weight is the definitely the hardest part, but with quite a few polymer lowers and uppers out there now it could be possible to find the right combination of parts. You'll want the lightest profile barrel you can find as well.

I've always kind of wanted to build something like this using a barrel with no gas port to be legal

Id hate to buy parts thinking it will be under 50oz, build it and have it be over the limit lol.

Mine are both factory original carbon-15.
The older one is a Professional Ordnance with a non-fluted non-stainless barrel and allen-screwed compensator.
The newer one is a Bushmaster with a stainless barrel and an air-hose type fitting on the compensator.
Both use shortened bolt carriers and non-standard recoil springs and buffers.
They both have standard fire control group parts (not polymer) with ALG ACT triggers.

I bought 2 of the extar ar15 pistols. ... they are 48oz with the hand guards. .... Since the hand guard is illegal anyway,  now it weighs less.....I silver soldered the brake on

Are you in jersey?

I looked at them (on paper, not in person) when they came out, but couldn't find a NJ FFL to bring one in and do the mods then transfer it to me.
When you permanently attach the brake (after removing the handguards and other "shroud" components) can you still do a complete disassembly or are you limited to a partial teardown?

im going to do a mock up build without buying anything first, gonna get weights on everything so when I put it together I know im not over.  somehow the other day I came across something interesting.  its an ar15 "firearm" from franklin armory that dosent fall into any category as far as rifle, sbr, pistol or aow.  So its not considered a rifle because it dosent have a butt stock, its not an sbr because it dosent have a butt stock, its not a pistol because it has a forward grip and designed to be shot with two hands and its not an aow because it measures in at 26.3" overall inches.  So technically it dosent fall into any of those categories and it even comes with a letter from the atf explaining this.  but that dosent mean nj has some stupid law that says I cant have it, been researching and have a few calls in trying to figure this out.  Hope I get good news but being we are in jersey I know its going to be all bad... heres the link. it should read 26" not 23"

http://www.thetruthaboutguns.com/2011/10/foghorn/franklin-armorys-new-ar-15-is-neither-a-pistol-nor-a-rifle/

Partial tear down. ... Can't get anything passed the muzzle brake. ... Awesum brake by the way. ...true one handed ar shooting