193272
Rifling was of the " polygroove plain section " type , with 33 grooves increasing from 0 to 1 turn in 50 calibres ( i.e. 1 turn in 800 inches ) at the muzzle .
 None
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
 Entities:  
Answer:
 None