The Agawam M66M .22 Magnum rifle was produced primarily in the 1970s and early 1980s, so it is typically around 40 to 50 years old. Its value can vary widely based on condition, rarity, and market demand, generally ranging from $200 to $600. Collectors and enthusiasts often seek these rifles for their craftsmanship and historical significance. For an accurate valuation, it's best to consult a firearms appraiser or local gun shop.