I plan on picking up a Remington 870 (81191) PGO and then attaching a shockwave technologies witness protection style grip to it, and slicing the barrel off for a total length of 26.5 inches. I may eventually grab a +1 magazine extension and possibly a magpul fore-end for a slightly more futuristic approach.
I'll attach some images of what I'm going for.
A few question though.
First, how would you guys go about cutting the barrel?
I have been told to use a heavy duty pipe cutter, which seems like it might work, but I'd prefer an option bit more precision. I realize that Remington sells shorter than 18'' barrels but I've been told it's a hassle to purchase them and I'd rather not have to spend the money on a new barrel if I can re-purpose this one.
More importantly, how does one go about re-crowning the barrel?
Is there a simple way to do so? I would prefer not to go to a gunsmith as I dont want to have to argue the legality of the length, most of my local gunshops are surprisingly unfriendly, or tend to charge insane prices for any work. I also prefer the satisfaction of finishing a project on my own.
Next, does anyone know how the ATF views concealment of such?
I have been told that concealing such a firearm under a trenchcoat renders it an AOW as it is concealed on ones person. I do not plan on doing this, but would putting it in my vehicle as a "truck gun" in a concealed manner also cause the ATF to view it as an AOW?
What is the likleyhood of the ATF deciding that they no longer feel the same way about the legality of such, after the fact?
I know this has happened a few times before (Eg: Atkin Accelerator). Is this something I should fear? Is this were to happen what does one do?
What should I expect as far as recoil goes?
I've been told that birdshead grips tend to help with shotgun recoil, I've also been told that a barrel around 14'' tends to reduce recoil as there is less length for higher pressures to build behind the projectile. However, I figure you guys would probably have a better idea what I would be dealing with considering this is mainly an NFA gun forum.

