Fixing high ES

[Dave Zander]

Listen to the Alex Wheeler interview with Eric Cortina. You might be chasing the wrong rabbit.

 

[Keith Stone]

A lot of good suggestions mentioned above. Since you mentioned a bushing die I am assuming that’s how you are setting your neck tension. I have run into issues using a bushing so I switched to using the bushing to set 2-3thou tension then following with a mandrel to punch the necks back out to 1 thou. Wipe the graphite off the brass but leave it inside the necks for seating bullets

 

[Doom]

Is the 30 ES based on 5 rounds or 10? As for brass weight assuming the same lot, a one grain difference in brass weight is about the equivalent of 0.1 gr of powder, which you can assume is around 6 fps.

You haven't mentioned COAL but you did mention .030" of the lands. These bullets are not sensitive to seating depth so I wouldn't worry about jump and just seat at 2.800" COAL. If this decreases the volume it may improve your ignition.

 

[Doom]

You mentioned changing powder and I would be surprised if the powder/primer combination is an issue but trying 4064 is worth a try.

Can you post the chronograph data for each shot from your tests?

 

[JFrank]

Here’s 21 shots ran past a chrono, it’s easy to see with a simple elimination of three cases I’ve cut the ES in half, those cases also display a difference in weight. It’s still early in my testing to make any absolute claims, but I will continue to sort brass and follow the clues.