Rifle is related to Automatic. Automatic is related to Mechanical. Mechanical is a synonym of Technical. Technical is similar to Skilled. 
Rate is related to Fast. Fast is the opposite of Weak. 
Rifle <--RelatedTo--> Automatic <--RelatedTo--> Mechanical <--Synonym--> Technical <--SimilarTo--> Skilled 
Rate <--RelatedTo--> Fast <--Antonym--> Weak 