Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Too fragile

I have used both these aluminum bolts and the plastic bolts with my 80 lb. Cobra crossbow pistol and can tell you that the black plastic rear section of the aluminum bolts WILL break after only a few shots. I now use only the plastic bolts (they have metal target tips) sold by Amazon and other sites. The plastic bolts are far more durable. Sometimes the metal tip of the plastic bolts will pull off. These can be glued back on very easily. On the other hand, the aluminum bolts are not repairable. Also, contrary to another review here, the aluminum bolts are about 2-3 grams heavier than the plastic bolts. The plastic bolts are quite accurate and retain their shape even after hard hits. Hope this helps.