The Hexhead Replacement Breech plug is only for Pivot-Action and Break-Actions made in *2009 and before, these models would include: Optima Optima Pro Wolf Kodiak Kodiak Pro. The last two numbers of your serial number indicate the year your model was made- Example 61-13-??????-01 this model was made in 2001
Specifications:

Type
Caliber
Finish
Color	Silver
Capacity
Size
Material	Stainless Steel
Model	Hexhead
Quantity
Pieces	1