Sounds pretty good. If its Pa elk you don't have to be very picky. I have called them in improvising with a coyote howler. I would try and hit a bit of a higher pitch toward the end of the bugle and bring it back down if you know what I mean. Kinda like your fifth bugle. Sproul
Where are you hunting? If hunting out west get some cow calls of different sounds and tones. The outfitters and guides I have hunted with rely heavily on cow calls and we have called in many bulls with nothing more than a hoochie mama. Bugling seems better near peak of rut when the bulls are willing to fight. Just my experiences though.