[Super Nova Tactical Stock Rod Removal?]

Does anyone know how to remove the rod which the pistol grip and stock are on? I have removed both the stock, and pistol grip. The stock rod seems to be very tightly secured and the thin hex nut that holds it to the receiver will not budge.  
 

I have seen a forum here discussing the use of heat but this was to remove a M4 telescoping stock/recoil buffer or something of the sorts. 
 

Any information is appreciated, thank you.

[Benelli MR1, Beretta Rx4]

On 6/5/2020 at 2:18 PM, 1006 said:

So, there are evidently no interested MR1 users. I just finished another disappointing day at the range with the MR1. I have owned my MR1 since new, it is one of the first 600 made. I take to the range every now and then to try another load.

It simply will not consistently group any load which I have tried at better than 2.0MOA. It reminds me of an older Mini14. The bullets just scatter. I have used 55 to 68 grain bullets, W748, Varget, and BL(c)-2 in my attempts.

 

 

I am more than interested to hear what has been learned about the MR1 platform from personal experience. I just purchased one and would appreciate any input you guys may have.