I'm looking for advice as to what I can purchase that is simple to use and cheap to make some of my primer pockets in my 40-65 brass tighter. the cases I have are Starline and Winchester, about 50 of each, they have been re loaded over 100 times each and now I have about ten that won't hold a primer without it falling out. As it may fall out into the action of my rifle I would like to avoid this happening if possible.
Mike.
PS,I could of course just form some more cases from new brass, but I'm curious to see just how many re loads I can get out of a case before it splits or becomes unusable for some reason.

Mick B, many tools to clean and open pockets. Not so much to tighten. Sinclair used to sell a primer pocket peener. But they are gone now. Several on line to tighten Shotgun pockets. 
Take the case and find a rod that will slide into the case to the head then use a small steel ball slightly larger than the pocket set on the primer hole tap the ball with a brass hammer and that will tighten the mouth of the pocket enough to hold the primer in place for. 10-15 reloads.
Best to use new cases if common but some odd calibers where the cases are a kings ransom it works. Best used with black powder loads. Hope this helps.

Rather than a ball, a dull 1/4" (OK, 6mm) arch punch.  In principle this is how military primers are crimped in, isn't it?

When swaging 30-30 cases to 32-35, the primer pockets got too small and had to be opened up for primers to fit.
The 32-35 base is much smaller than 30-30. This swaging was a LOT of work.

drop primer in pocket/smear grease on primer and pocket/load/fire?? 

scotch tape on primer and case mouth?