Start with a single, sharp grunt to get attention. Use medium volume and hold for about 0.5 seconds. This establishes the sequence.
Follow with 3-5 rapid grunts in quick succession. Each grunt should be shorter and slightly softer than the initial grunt. Space them 0.2-0.3 seconds apart.
End with 1-2 softer grunts as the "buck" moves away. This creates realism and urgency, suggesting the buck is actively trailing a doe.
Total sequence: 3-5 seconds. Wait 15-30 minutes between sequences. During peak rut, you can call more aggressively with sequences every 10-15 minutes.