My wife likes to shoot arrows at targets. She uses a relatively lightweight draw compound bow now. We have been talking about her trying a crossbow. I did a quick search online and found junior models with draw weights from 15 to 60 lbs.
I suspect 15lbs is not going to give good results, and 60lbs is more than she is using now. Presumably there is some value in the middle that is optimal for target practice only.
What is the minimum draw weight for a target practice only crossbow?
You are comparing apples to oranges here. You can have a much much higher pull weight on a crossbow, simply because it is easier and you can use mechanical advantage.
If you look at history, the advantages of a crossbow is that the archers didn't need to have the same amount of physical strength required to pull a long bow.
For example,
That said, most of the better hunting crossbows are in the 150 to 175 pounds range, with a few topping out over 200 pounds. In general, bigger is better—or in this case, faster. Keep in mind that you can go too heavy, too, as at least one state—Ohio—has a maximum allowable draw weight of 200 pounds.
200 lbs incidentally is the world record for a longbow. =
Mark Stretton (UK) drew a longbow weighing 90 kg (200 lb) to the maximum draw on an arrow of 82.5 cm (32 ½ in) at the shooting grounds of The Bath Archers, Somerset, UK on 15 August 2004.
Now for your actual question, heavier pull weights mean faster arrows and therefore less drop and more accuracy. At some point however, a heavier pull will be impossible to pull back.
Where that point is will depend on the person. To find that point I would suggest that you visit a physical store and ask to attempt to cock one before actually buying it.
Personally, I would doubt that a 60lb pull would be too much for an average person.
