Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Poor Results with Porta Nails

Recently purchased Porta-Nails 421P kit. Nothing but trouble with jamming. Contacted Porta-Nails and they sent an update kit which I installed. Gun would work for about 10-12 nails and still jams. Re-adjust, it would work again for a few more nails before jamming again. Continually needed to be re-adjusted. Totally dissatisfied with this product. All this in less than 2 boxes of nails.Ended up purchasing a manual nailer which never let me down.