MCH Gauss Barrel Rapidfire GCD bug.

Time: July 14th, 2015 - 2:01 pm.
Frequency: All the time if executing the same way.
World name: Moogle
Character name: Hutan Furh
NPC name: N/A
Monster name: N/A
Class/Level: Machinist / 58 - Bug require lv 52 for Gauss barrel.
Party or solo: Solo, although also happens in party.
In-game time: 1:01 pm.
Area and coordinates: N/A
Steps:
1. Use Rapid fire
2. Use a GCD instantly
3. The cast will have a cast time, but still consume a rapid fire stack.
4. This means I only get 2 instant casts, instead of the desired 3.
I have tested to see if you get 3 instant casts and you indeed do, the bug only happens if the GCD is activated instantly after casting Rapid fire (before the buff is actually applied) but it still consumes one of the stacks. It might be a latency issue, but it seems to have an effect on my gameplay nevertheless.

Connection Specs
- Type of internet connection/provider: Fiber 90/90 from Energimidt - I play with a bit over 100ms.

So I did some more testing, and it seems like a latency issue. Sometimes it makes my first split shot/hot shot instant cast but other times it doesn't.
So the problem here lies in that the rapid fire buff is applied too late, so when you use the hot shot it still does the cast bar and when it is done your rapid fire buff is applied and counts it towards the instant cast counter.