How do you load the primers in the primer tube?

you have to lay out the primers head side up and then take the tube and push down on each primer as it fills the tube. Once all the primers are in the tube push the last ones down and insert the cotter key and they will be locked in the tube. Just make sure you use the large tube for the large primers and the small tube for the small tube. If you put the small primers in the large tube they have a chance of flipping over in the tube as they come out.

I need 209 primers for home security trip alarm what kind of deprimer tool would I need?

This is a PRIMING tool not a depriming tool and it doesnt do 209s, only rifle and pistol primers.

It will not load a 9mm. It will insert a primer in a 9mm

What are the benefits of using the rcbs autolader over the manual priming tool on my redding t7 press?

I prime all my brass seperatley from using the Hornady AP progressive press auto primer only because it is a little easier to verify that the primer is set properly before going thru the powder and bullet stage. Piece of mind I guess.