My Sport had the same condition after I swapped out the front A2 sight with a low profie gas block.
The idiot who swapped it out (me), failed to perform the simple test that Grover described above. Once aligned properly, the solvent ran out the barrel...problem solved.
I would think there would be enough room theoretically, but you're limited in where you could mount the AFG. You may not like the feel when shouldering the rifle, and not have much room to move it.
I got mine off of Amazon, don't remember the manufacturer. Search the archives here, there's a lot of info about this topic in prior threads.
Good luck.
I got mine from Amazon, free shipping, etc. I've seen a tool for sale that is recommended to depress the collar holding on the handguard. It's not necessary. You can do it your self or have someone depress the collar for you.
Best of luck
What is your long term shooting plan? Are you going to invest in optics? I think your money would be better spent there. I've left my magpul on there, zero'd the irons and left them alone. I shoot with a scope and never thought of putting money into sights I'll probably never have to use.
I shoot it all the time. Some in-door ranges won't let you shoot it, so check before you spend your money.
It's filthy ammo and I would recommend a thorough cleaning after you hit the range.