Depends on the circumstances..
Early season blind calling, just 3-4, soft 1-2sec urrrps.
I start calling about 10 minutes before shooting light about every half hour or so until 10am, by then bucks are most likely bedded.
Early season sight calling, quite short urrrrp until he responds, increase the volume if necessary until he reacts by stopping or looking, then stop, hit it again if he walks away.
But once he's out of site don't do it again, some bucks will circle back on a call.
Halloween on and through the rut I get loud, just to the point before it starts to sound like a duck call.
I'll also throw in longer urrrrrrrrrrrrrrrrrps combined with clicks, I make clicks by popping my lips against the tube forcing short burst of air through the tube, also popping your tongue against the roof of your mouth works.
If you've heard some bucks that are all frenzied up, you'd swear the sounds had to be fake, especially when on a doe that won't capitulate.
It's like people though, they all have a unique sound.
Keep your ear to the ground, most bucks unless they are bawling/growling I can only hear them within 50 yards.
Some bucks grunt every step, some grunt every 4-6 steps or when they stop.
And I rarely hear bucks grunting before Halloween, but it doesn't stop me from calling before then.
Practice practice practice, experiment on deer you see, get a feel for the volume it takes to illicit a response.
Get on youtube and search buck grunts, it'll help some.
Last edited by onion721; 08-22-2011 at 07:04 PM.