Case filled past base of shoulder a no no?

[Stats Shooter]

I have dealt with compressed loads a lot. I like the case to be full enough that its orientation has little or no impact on primer to powder gap, but not compressed enough bullet seating becomes a problem. I have tried up to 10 % compressed and I get inconsistent seating depths. Even with a drop tube it can be an issue.

I have never seen the bullet get pushed back out, but that doesn't mean it doesn't happen. As a rule I try and stay at or below 105%, but it depends on the powder. Ball powders like H335 doesn't compress well, while H1000 or 4831 does.

4064 probably would compress, but I use 41 gr behind a 175 gr match king and find no compression.

 

[Roadkill2228]

That’s very true about ball powder not compressing as well. One thing I’ll add is that while I’ve never personally had issues with standard primers in the past, I’ve switched to magnum primers whenever I’m loading compressed, and especially with ball powder, to ensure consistent and clean ignition, especially relevant where I live and hunt as it’s in winter and often below -20 Celsius. Again, I’ve had no bad experiences with standard primers, but with very compressed loads the magnum primers actually lower extreme spreads and you can’t be too careful.