"Shall" is becoming archaic.
"I will" implies a sense of purpose or determination.
"I shall" simply states the fact.
Shall | Define Shall at Dictionary.com
The rule continues that to express determination,will is used in thefirst person ( We will win the battle ) and shall in the other two persons( You shall not bully us. They shall not pass ). Whether this rule wasever widely observed is doubtful. Today, will is used overwhelminglyin all three persons and in all types of speech and writing both for thesimple future and to express determination. Shall has some use in allpersons, chiefly in formal writing or speaking, to expressdetermination: I shall return. We shall overcome. Shall also occurs inthe language of laws and directives: All visitors shall observe postedregulations. Most educated native users of American English do notfollow the textbook rule in making a choice between shall and will. Seealso should.