OAL Consistency

[captn-tin]

Using 9mm RCBS dies in my 550B Dillon unit, I'm having a problem with maintaining correct OAL. Loading Extreme 115 gr HP plated bullets to 1.130 ", the 1st couple will be OK then start varying by .003 - .010". Same thing happens after reset the seater die. I'm also using a Lee factory crimp die in station 4 but I don't think that would have any affect on the length. Anyone out ther experience this problem. Could it be I'm expecting to much, just a 74 yr old nitpicker.

thanks for any help...captn-tin

[robert101]

I would not worry about a difference that small. If you are precision loading for long range and measuring to the ogive, then the difference would be a concern. For 9MM not an issue. I would make sure the extremes fit into the chamber.

[balmo]

0.010 is perfectly fine. I load with a give of 0.005

[JagerDog]

Cheap bullets are going to vary on where the seating die contacts on the bullet more so than more premium bullets. That said, it won't matter in your application.

[y-not]

I had the same situation happen.
My set up was correct, it was me making the variance.
I wasn't pulling the arm all the way thru till it bottomed out on the stroke.

[ysr_racer]

Cheap bullets are going to vary on where the seating die contacts on the bullet more so than more premium bullets. That said, it won't matter in your application.

Agreed, cast and cast/plated bullets can vary a little bit.

[racinjason233]

No worries on bought or cast boolits. Run and gun after chamber check. It’s 9mm. Develop your loads and keep pulling the bang switch.

[jmpgnr24k]

Agreed. That small of a difference won’t matter.

[9mmepiphany]

Loading Extreme 115 gr HP plated bullets

I'm also using a Lee factory crimp die in station 4 but I don't think that would have any affect on the length.

The Dillon 550 doesn't suffer from the same plate tilt that the other Dillon presses do due to differences in the shellplates. So while the amount of variance wouldn't be excessive for a progressive press, it is a bit unusual for a 550.

The two points that I quoted above would be contributing factors.
1. Extreme bullets aren't really known for their consistency; even their HP bullets.
2. The Lee FCD does indeed affect the OAL due to it's post-seating resizing feature

[JagerDog]

The Dillon 550 doesn't suffer from the same plate tilt that the other Dillon presses do due to differences in the shellplates. So while the amount of variance wouldn't be excessive for a progressive press, it is a bit unusual for a 550.

The two points that I quoted above would be contributing factors.
1. Extreme bullets aren't really known for their consistency; even their HP bullets.
2. The Lee FCD does indeed affect the OAL due to it's post-seating resizing feature

The Lee FCD doesn't "resize" bottleneck cartridges.

[9mmepiphany]

The Lee FCD doesn't "resize" bottleneck cartridges.

When did the 9x19mm (the cartridge under discussion) become a bottleneck cartridge?

[tanks]

One other thing to make sure when setting up your seater die is to make sure all other stations have brass in them. Shell plate flex changes based on number of stations that are full.

[JagerDog]

When did the 9x19mm (the cartridge under discussion) become a bottleneck cartridge?

My bad. I mixed it up with another thread.