Complex sentence: The Martini-Henry was copied on a large scale by North West Frontier gunsmiths, their weapons were of a poorer quality than those made by RSAF Enfield, but accurate down to the proof markings.
Split into simpler sentences: The Martini-Henry was copied on a large scale by North West Frontier gunsmiths. Their weapons were of a poorer quality than those made by RSAF Enfield, but accurate down to the proof markings.