HK-91 NJ BFA conversion issue

[tenhunter]

I have an unusual question and will definitely need the help of experts before I get to far along in my quest. I enjoy doing modern combat simulations and using blank fire weapons, I am considering purchasing a HK-91 but have some issues I need to work through and would love feedback. I am comfortable with this gun, as far as using it and basic take-down. I am also somewhat of a novice to rifle ownership and will be inclined to ask stupid questions.

NJ requires the "flash hider" to be pinned or welded to the barrel. I may simply just not be aware of when a rifle is a rifle, but is there anyway to simply buy a receiver with a barrel and pin a BFA to it so I can switch out the barrel? Any thoughts on how I could be set up to use the gun for regular fire and blank fire without needing two guns?

[UMP45 ENTRY]

The HK91 is banned in NJ by name. You can however purchase a PTR91 or a different type of similar clone. Also, flash hiders and threaded barrels are illegal in NJ on a semi-auto rifle with a detachable magazine. You must perminately pin/weld a muzzle brake on the barrel so it cannot be removed. Unless you can find a way to mount a BFA onto your muzzle brake, I’d say it’s not in the cards.

[tenhunter]

Is it technically illegal to own a receiver and barrel? If I use the BFA in different states would it be possible to own a separate combo that I build on site out of state?

[Anopstyx]

The barrel is not easily removable on hk9x series weapons. They need to be pressed out with a 20 ton press and when you put a new barrel in a flash hider or anything on the muzzle needs to be removed before it will fit the the rear of the trunnion. Then the barrel drilled and pinned through the side of the receiver and trunnion. It would be easier to pin the bfa on and leave it there and when out of state and wanting to use it remove the pin and shoot regular rounds but replace the bfa going into ban States