Help! Mossberg 590 Shockwave Forend

[Kooenaybackwoods]

I recently picked up a Mossberg FDE shockwave with the 14 inch barrel. I was trying to install a magpul forend, a very simple and popular upgrade. Unfortunately the castle nut that hold the forend on would not budge. I have the correct metal tool to unscrew it and it is so stuck that now it is just spinning the metal tube Inside the hand guard. The action tube assembly is what most call it. Maybe the nut was cross threaded?
Has anyone experienced this? What can I do now?

 

[badboybeeson]

Well you have a few problems
You may need zome het toctake pf the nut.
2 the magpul forend wont fit.
As the bbl lug is in a different spot and th3 forend pump metal is shorter.
This is what we we have been using
https://sjhardware.com/ergo-short-m-lok-mossberg-500-590-tri-rail-shockwave-only/

 

[Kooenaybackwoods]

I've used heat, didn't make a difference. And actually you can buy modified magpul forends that fit the shockwave which is what I have.

 

[easy]

Have you tried clamping the bars in a vice for a better hold on it? If you have a vice. Try soaking it with some liquid wrench first.
I doubt it would be cross threaded all way down. Might be seized with corrosion or thread locker. Was this a new gun you bought?

 

[Butcherbill]

Depending on the nut wrench you have you might get more torque putting it in a vise and twisting it by the forend, you’ll be able to get a better grip on the forend as you try to break the nut loose.