There's no such thing as a "wheat nickel", only wheat-back cents. A 1906 nickel would be a Liberty Head nickel, with a picture of Miss Liberty on the front and a large V (the Roman numeral for 5) on the back.
what does a 1857 nickel look like
The value of the 1906 V nickel varies greatly depending on the condition of the coin. This nickel can be worth as much as about 4 dollars depending on its definition.
There is no such thing as a 1906 Indian head nickel(*). The first nickel with that design was issued in 1913. The previous design is called a Liberty nickel; you can find a list of prices at the attached link.
Please check your coin again and post a new question. Buffalo nickels were made from 1913 to 1938, and were never struck in silver. A 1906 nickel would be called a Liberty Head nickel, and like all nickels except the famous "war nickels" of 1942-45, it's made of an alloy of copper and nickel, hence the name "nickel".
1906 is a common date for Liberty Head nickels, most circulated coins are valued at $1.00-$3.00
The only silver nickels ever made were made in 1942-1945. These nickels contain 35% silver. So a 1906 US silver nickel is worth nothing because there is nothing like that. See the related question below for the value of a 1906 US nickel.
It's a Liberty Head Nickel the date 1906 is very common, values are at $2.00-$5.00 for average coins
In good condition about $2.00
Must be appraised by a professional.
A US one cent coin dated 1906 is a Indian Head (1859-1909) cent.
Additional information is necessary to properly value your rifle. There were two models available in the Winchester Model 1906. One had a straight stock and the other had a pistol grip stock and was called a Model 1906 Expert. Which one do you have? Also, you did not say, if your rifle was partially trimmed in nickel or was fully nickel trimmed?
In average condition, it's worth about a dollar.