They do break sometimes however, but with practice you can get really good at making them.
Another fun thing to make - if you love DIY projects - is to make a double limbed bow which is much more powerful. See the videos further below to see what I mean.
For hunting purposes please remember that your bow needs to be over 40 lbs to be legal for hunting (over 48.5 if you want to hunt for moose, elk or black bear) - otherwise you are more likely to injure the animal and not actually kill it. Most deer hunters use 45 lbs and most moose hunters use 50 lbs. Some hunters go over that, but it is unnecessary and overkill.
Below are some photos of similar double limb bows, made from wood / etc.