M2 Steady Grip Installation Issues

[VaTuRkStOmPeR]

I purchased a used Benelli steady grip for the M2 Compact 20 ga I bought late this spring. The  stock is in great shape but it appears the circular plastic piece inside it, located near the swivel adapter, is impeding the stock from reaching the receiver.

I can only get the stock within 1/2" of the receiver.  Has anyone ever encountered this issue? Any solutions?

[Horrendo Revolver]

Just looked up the Steady Grip stock and it shows there is a part that must be purchased for it to work.  It's called a stock swivel plate.  Did the stock you purchased come with one?

http://www.midwestgunworks.com/mm5/merchant.mvc?Screen=PROD&Store_Code=&Product_Code=83158&Category_Code=benelli-camo-stocks-forends