Semi-auto is not legal for deer in Pa. I have a 7.62x39 bolt action I built years ago before a commercial version was available. I used a 7.7 Arisaka barrel and action. The barrel is .311-.312 and I have tried both .311 bullets and .308 bullets. The .308 150 Grain Remington Corlokt bullets shoot the best. At 100 yards it shoots as good or better than most new rifles. I have shot a couple deer over the years with it. I think one at about 100-120 yards. One right between the eyes at about 80 yards. One running pretty close but it soon dropped. Although I have never used them for deer, you probably will be O.K. with factory loaded 123-125 soft points if you stay away from the Russian and Chinese scrap. The other poster may be right, your rifle may have a .308 barrel on it anyway.