Cow calls are generally the best call to bring an elk in with, you can attract both cows and bulls, old or young. The bugle is a great locator but I wouldn't put my faith in it to bring in a bull....it could but i think today it is is more or less considered a locator. Also don't forget about things like raking a tree to simulate a fight or bull rubbing on a tree or even the glunking sound.
Think of it as turkey hunting where you can use a cobination of several calls to get the desired outcome. Some bulls will respond with a bugle to the full bugle or some may only answer to a whistle or chuckle. Some may not answer either but may come in silent to a cow call. you just really never know how an animal may really react to anything.
If you want to knwo about call brand there are several good ones. Abe & Sons, Primos, Jones, Quaker Boy, Carolton, etc. I would go for either the Abe & Sons or the Primos myself but that is just my opinion. The Jones Pursuader is a good bugle tube as well. The Primos Hoochie Mama is about the easiest to use cow call made and the Terminator is a great bugle call.
Here are some common elk sounds to get yourself familiar too.
Maternal Mew - used to bring the calf in to nurse, Calf Mew - used when responding to their mothers, Social Contact Mew - searching for or maintaining contact with the herd, The Glug - used by bulls when herding the cows, Then you have the Bugle, the Roar, the Chuckle and any combo of those used by a bull to make their bugle sequence. Some may do the full bugle sequence or some may roar and then bugle or some may roar and chuckle.....as you can see no set way for a bullto do this!
Aghh I forgot the one everyone talks about....The Estrus Call! Recently somepeopel who study elk have determined that this call isnot actually a breeding call but more of a social call that dosn't really tie into the breeding process. i have no clue since I am not expert on elk....There logic makes sense to me so I question all this marketing hype put out by game call companies. The theory makes sense to me that they really do not need a call since they are in herds with abull anyway. It makes sense to me this could just be a highly vocal sound used by lost or cows looking for the herd again and a satlelite bull could be coming in to try & get lucky before she gets back to the herd.
To learn more about elk sounds go to
www.trmichels.com
In my opinion this guy is the cats meow of understanding elk sounds.