Yup 1905 pattern service dress cap with the '08 chinstrap, very typical of 19-14-15 issue up until the soft SD cap was introduced as steel helmets became available. This style was worn in Canada in regular service until the end of the war, versus the soft caps.
Nice looking artillery service dress cap. Here's a pic of my granddad at home in Sudbury, Ontario (1915?) wearing his 7 button Canadian made tunic and 1905 SD Cap with artillery insignia. Could it be that you have his cap????
thanks for showing, Cheers