Are you making sure that as you go into your non twisted grip handspring that your head is going down as far as possible?

Non twisted grip handspring: as you step down to go into it, make sure that your above arm is bent - u need that bend to be able to pull yourself up. A must is that your head follows the arm that will be the lower one. Make sure you "glue" your ear to the arm that will be the lower one.... The main reason for not being able to lift legs all the way is that the head is not down far enough which makes your body twisted and your bottom not lift...

Twisted Grip handspring: again on this one you will need your head to be down as far as possible. On this one use your upper arm to lift up and the lower one to push away - make sure that your lower arm is fully extended. With your kicking leg, make sure that you kick forward and then back.... as you twist your hips, tuck knees to chest and then engage arms to straighten body up....

Main thing is the head going down as your feet are coming up... Keep practicing and you will get it! Believe!