My pistol is just about complete.

I have a front sight base that i ground down and looks like a little more work it will fit inside the rail.

However, when looking at the barrel through the vent holds it looks like i will find complications. Problems getting the studs in the FSB and barrel because metal from the rail prevents me from putting them in place.

I have seen the exact upper on a SBR(I think from MSTN.com) so i know its not impossible.

Do i need a new gas block?
Is there something obvious i am forgetting?

Thanks.

Would you be able to post some photos?
That would help out!

I wanted to do a F/F Carbon forend on a pistol build but I wanted everything inside the tube.  
That would be a no go with .223 but a hell yeah with 9mm or .45 since we dont need a gas block.  I am still trying to figure out a way to get everything squared up on this idea.