It is my understanding that most Parkers made before 1895 were overbored. I have two 12 gauge Parkers with twist barrels. One was mfg. in 1877 and the other in 1893. The 1877 gun is a lifter with a .748 and .750 bore size. The other is a top lever grade 1 with .751 and .752 bore size. I have heard that .750 on older Parker 12 gauge guns is common. Is this correct? I am hoping others will chime in with their actual measurements of their guns to see if we see a trend here. Thanks!