Headbutt loop questions

I’m trying to practice the headbutt loop, but I seem to be doing something wrong…

After mp headbutt, standing lp never comboes. I’m assuming it’s a range issue, the headbutt needs to travel a bit before it hits because it has more than 1 active frame, correct? I’m trying (hold)hk, lp, mpheadbutt, lp… do I have to leave some space before I start the combo or can I do it from point blank?

Also, what is the maximum number of headbutts you can get? I imagine it’s optimal to end with something other than the headbutt, tackle maybe?

Execution was never my strong suit, I’d appreciate any pointers, thanks!

I found Foxx’s headbutt guide to be really useful for headbutt loops. It has a bunch of set ups too.