I have a Skymaster F-18C and I have them screwed in for now but I am just not comfortable with that setup. Just seems too flimsy on the wing, nothing hard to screw into...

how are others attaching them? I have heard magnets too...

please post pics if ya got em!

There is an argument that the attachment being none too solid is a good thing, as if the get caught in grass or something they will pull out with the minimum of damage. If you are not happy you need to open up the wingtips and fit hardwood blocks to screw into.
Magnets should also works. Again you will need to mount these on hardwood blocks.
Gets some that have good depth and then roughen the back and the circumference with a Permagrit tool. On the rails insert a piece of ply to back them up to. It is really important to get the mating surfaces flat. In the wingtip make a piece of thick ply with a hole in it the size of the magnet and glue one in there the correct depth to match face to face with the one in the tip. Make two to attach the rail and fix them with epoxy filled with cotton fibre. It takes too long for hysol to go off and any way you need minute quantities only.
John

Couple different ways, on my f16s, i used the small screws to mount, but then drilled a 1/ hole thru the missile and rail, and into the wingtip, used a syringe and injected hysol into the wingtip,rail, and missile. Then brushed hyson ao a 1/8 carbon tube with some nothches i put on it with a file. Slid em in, cleaned the excess, and taped to hold position while drying. They aint never coming off. And yes there is the risk of damaging the wing, but i have seen em break right at the rail at the leading edge which can be fixed fairly easily.

I usually use 4-40 nylon bolts. They will hold very well, but will shear off if you catch a wingtip on something.

with t nuts?

I CA the rail to the wing, and then use white glue to attach the AIM9X to the rail. So far so good.