I'm far from an expert, but I'm pretty sure all these rifles were freebored at the factory. However, there should be folks on this forum more knowledgeable than I am that can shed some light on this.
You can easily tell freebore when you seat bullets to OALs of 3.30"+ and the bullets are still a ways from being engraved.
The "Pet Loads" may be fine, but I would approach the Ken Waters data cautiously as I would any old data. I haven't read that article in a while, but he used a rifle built on a commercial '98 Mauser action, I believe. Ken Waters was usually conservative in his load development. As I recall, his rifle was not freebored. As a result, with your S&L, you may may get lower velocities than listed in the Waters' report.
Hornady book data appears to be old, but their H4831 data / max loads jive with what I've found using the Hornady 154 grain Spire Point, though my velocities are lower than Hornady's. Here again, Hornady's test rifle was a '98 Mauser that probably was not freebored, though that's not mentioned in the manual.
I have a NULA in 7x61 (26" barrel, 1 in 10" twist) that is not freebored. Out of necessity, I must treat my two rifles as if they were chambered for different cartridges. The NULA takes several grains less powder to achieve a higher velocity than I can get with the S&L. Bullets must be seated much deeper for use in the NULA.
I've been working lately with the Nosler 140 Partition and H4831 in the S&L, but haven't yet been able to get it to group well with the consistency of the Barnes. May have to try H4350.
