these darts are extremely durable and reliable. the large spearhead cuts i wider wound channel than other .40 cal darts. the heavier weight of these darts keeps the wind from affecting it greatly, aids in durability and knockdown power. the downside and upside of the dart is you have to use more lung power. its bad because you might flinch, throwing you off target slightly, or dramatically(with practice this can be eliminated). the good part of using more lung power is that it trains you to use that lung power so when you switch to a lighter dart(such as spearhead or wire darts) you will have more power and accuracy. bottom line these are excelent hunting darts that every .40 caliber blowgun hunter needs.