Variation in OAL

[JTMaddox]

reloading 9mm on my dillon 650 I seem to have a fairly significant variation in OAL. If i'm trying to reload to 1.20 OAL I will see everything from 1.15 to 1.25 when I check with calipers

I have tried everything i have read might be the cause including:

- made sure shell plate is tightened down
- checked inside of seating die for any kind of buildup
- loosened all my dies, run the shellplate up with rounds in each station and retightened dies with shellplate in up position

Based on other reloaders i've talked to this seems like a lot of variation, even for mixed brass. How much variation do most people consider to be acceptable? Has anyone else had this same issue? What can be done to resolve it?

 

[Wall]

what kind of dies & bullets?
My lee dies seat using the ogive not the end of the bullet.
If there is a variation in length of bullets, it still seats the same amount into the case.
So I'm not so concerned with variation, but the variation you gave does seem pretty extreme.

 

[technetium-99m]

Are you missing a digit? I'm not sure I know of any set of 9mm components that will produce a cartridge of 1.25. That's 38 super and 45 length.

 

[Wall]

Are you missing a digit? I'm not sure I know of any set of 9mm components that will produce a cartridge of 1.25. That's 38 super and 45 length.

I went with the assumption he meant 1.115 - 1.125, but yeah he said he's trying for 1.20. Damn I don't even load my .40 that long for my STI.

JT, What gun are you loading for?
Are you trying to get them to 1.120 not 1.20?

 

[technetium-99m]

If thats the case then just roll with it. Plus or minus 5 thou is fine.

 

[JTMaddox]

what kind of dies & bullets?
My lee dies seat using the ogive not the end of the bullet.
If there is a variation in length of bullets, it still seats the same amount into the case.
So I'm not so concerned with variation, but the variation you gave does seem pretty extreme.

dillon dies, xtreme plated 147gn

 

[JTMaddox]

Are you missing a digit? I'm not sure I know of any set of 9mm components that will produce a cartridge of 1.25. That's 38 super and 45 length.

yes, 1.125... fingers faster than brain (as most things are for me)

 

[JTMaddox]

I went with the assumption he meant 1.115 - 1.125, but yeah he said he's trying for 1.20. Damn I don't even load my .40 that long for my STI.

JT, What gun are you loading for?
Are you trying to get them to 1.120 not 1.20?

glock 17L with storm lake barrel. yes, i meant 1.120 with the extremes being 1.115 and 1.125 respectively...sorry for the confusion...im actually thinking of decreasing overall length to 1.110 but still wondering if that amount of variation is normal...

 

[Wall]

glock 17L with storm lake barrel. yes, i meant 1.120 with the extremes being 1.115 and 1.125 respectively...sorry for the confusion...im actually thinking of decreasing overall length to 1.110 but still wondering if that amount of variation is normal...

I load 9mm to 1.135.
If your die seats using the ogive, the variances in length between bullets will give you what you're seeing.
The length from the base to the ogive will be consistent, but not to the bullet tip.

As GT said, Plus or minus 5 thou is fine.

 

[technetium-99m]

If your die seats using the ogive, the variances in length between bullets will give you what you're seeing.

The length from the base to the ogive will be consistent, but not to the bullet tip.

Bingo right there.