Need some advice.

I'm creating my low level Granite maul pure and I decided to cannon my range from 1-70, I want to have a high range and str level for my combat, however I don't want my HP too low but I want it in the Middle... Should I use cannon/darts or just stick to cannoning and train hp while training str?

STATS AT THE MOMENT:
50 Attack
58 Strength
1 Defence
48 HP
70 Range
1 Prayer
Combat: 47