I am often asked this question: When anchoring something into a brick wall is it better to install the anchor in the brick or the mortar?
I could answer it by saying it depends but in most cases it is better to anchor into the mortar joint. Brick is sometimes soft and can crumble or hard and it can crack with the use of a hammer drill. If something does go wrong and the brick cracks you have a problem. If something goes wrong in the mortar joint it is easy to repair. So drill the hole with a hammer drill into the mortar joint, before inserting the anchor put some silicone or epoxy filler in the hole and set the anchor. This will insure a snug and permanent fit.