See pic. The enfield round is on the left. Other is a standard 3 ring minie and the wood plug is still in the bottom although you can't see it in the picture. It is possible that the 149th PA traded their enfields for springfields sometime along the way. A lot of this was going on in the Union army. In 1864 if he still had his enfield he was probably using the standard federal 3 ring minie sized to fire in the enfield and the springfield. This made supplying ammunition to troops in battle much easier. Also, there are not many enfield bullets found in late war US camps. Most are found in CS positions since they used them all through the war.