 After the war , a shorter @-@ barrelled version of the Model 1897 was marketed by Winchester as a riot gun . Messengers of The American Express Company were armed with this weapon as were various police departments throughout the US . The differences between this riot version and the trench version were the riot version lacked the heat shield and bayonet lug , and all trench guns were equipped with sling swivels , whereas most riot guns were not . 
