I am trying to create a gun (I'm using forge for 1.8.9) and I'm running into some issues relating to firing methods. There are three different ways I have tried doing it:

1. Just firing bullets in the onItemRightClick method. Disadvantage: this method gets called MUCH less frequently than regular ticks, so guns fire very slowly

2. Firing bullets in the onUsingTick method. Disadvantage: since I'm modifying the NBT of  the item, this method has very odd behavior and causes the gun to never stop firing

3. Checking for key presses in the onUdpate method. Disadvantage: doesn't work on servers.

Is there some solution or better method I'm not seeing?

The fastest Minecraft can do anything is on a per-tick basis. Theoretically, someone might be able to right-click faster than once per tick and thus fire more bullets than any other method, but I haven't tested that. At worst, #onItemRightClick will be just as fast (or slow, depending on your perspective) as any of the tick methods.

 

You can, however, simulate faster than once-per-tick by spawning multiple bullets per click/tick with their position offset so that bullet 1 starts further away than bullet 2, e.g. by 1/2 to several block distances between each bullet. You could also give them slightly different trajectories to emulate 'spray' or not-quite-perfect accuracy (take a look at EntitySkeleton's ranged attack for an example).