[MGK]

Hi all

A question, just to gain some insight from those a little more experienced with the 550 than I.

I am reloading 9mm on a Dillon 550 using Lee Dies and mixed brass with 3.9 gr Titegroup and 125 gr LRN. I load a single round at a time and I get an OAL from 1.10 to 1.14. I go to progressive mode and the OAL jumps to between 1.15 and 1.21. The OAL seems to run between 1.14 and 1.16 with an occasional 1.21 There is some flex in the tool head, is this the cause? Any other ideas, just curious. I haven't had any feed problems, but I don't want either. What has been your experience?

MGK

[Dave R]

I would check your load data carefully, and re-do any that are UNDER the minimum OAL. To quote from Speer #13, P. 500:

"UNDER NO CONDITIONS SHOULD THE BULLETS BE LOADED SHORTER THAN THE LISTED LENGTHS. 9mm case capacity is relatively small and seating a bulet deeper than indicated can cause excessive pressures..."

Too long is safer than too short. the only danger with too long is, will it fit in your mag, and will it contact rifling.

[added] I don't have any experience with the 550, so can't help you there. Just being cautious.

[JA]

On a progressive press if the OAL gets longer when running it as oposed to running a single cartridge this means that the other dies are not letting the shell plate move up as much.
One or more of the dies or depriming pin is not letting the shell plate move fully when brass are in them.
I would sugest you check/reset you dies or set the OAL only when there are cases in all the stations.

[Steve Smith]

Try setting all of the dies with all stations loaded.

[Mikul]

JA is wise my son. Reset your dies. It's probably the sizing die. Remember to back off 1/2 turn after it reached the shellplate. If it isn't the dies, your may be short-stroking occassionally.

My 550b fluctuates about .03" in OAL so 1.14 to 1.16 is normal, but 1.21 isn't.