Slow response (time) to (DSLR) shutter trigger/release is a multi-level problem. Consider these:
1. Memory buffering / CF speed
2. JPEG compression
3. CPU image processing speed
4. Mirror-return (flip) speed limit (pertaining to DSLR, no mirror for rangefinder cams)
5. Auto-focus (usually dependence on lens' spec, unless you are talking about old contax SLR system)
6. Very important: shutter speed e.g. set at 1-seconds either automatically or manually means a ONE full second delay in exposure
7. Point 6 could linked/due to auto-exposure / compensation
8. Battery weak charge
9. Finally read the stated specification of your camera multi-shot limits