I experimented a bit with OAL using my Cooper MTV in .223 AI today.
Using 40 grain Sierra BlitzKings and fireformed brass, I loaded five cartridges with the following OALs (measured using a Sinclair comparator):
2.805
2.825
2.845
2.865
2.885
2.905
2.925
2.945
2.965
Now for the record, the leade on this gun is so long that I can't determine the max length with the short 40 grain bullets. It doesn't matter much anyway, as the numbers are only relevant to this rifle.
The group on the top left had the bullet seat the farthest from the lands. As the bullet was moved closer and closer the groups tightened significantly.
Using 40 grain Sierra BlitzKings and fireformed brass, I loaded five cartridges with the following OALs (measured using a Sinclair comparator):
2.805
2.825
2.845
2.865
2.885
2.905
2.925
2.945
2.965
Now for the record, the leade on this gun is so long that I can't determine the max length with the short 40 grain bullets. It doesn't matter much anyway, as the numbers are only relevant to this rifle.
The group on the top left had the bullet seat the farthest from the lands. As the bullet was moved closer and closer the groups tightened significantly.