New to 550b - Little help please

[Angrysquirrel]

I have been reloading for about 6 years so I have some experience, not an expert and always learning.

I just purchased and set up my 550b. I did a test run of 9mm and 45 ACP.  On both runs, I had the OAL set exactly wher I wanted it, when seating bullet with one case in press.  When I went to "production" of my test 10 cartridges each the OAL came out a few thousands long.  I ran the rounds back through the seating die one at a time and the OAL came out perfect. Is it a known set up issue to have the OAL grow with more than one case in the press?

Also, are you using the Dillon lock rings or something different?

Thanks. 

[Flatland Shooter]

I don't remember hearing  of changes to the  AOL when all stations had brass in them or not.  But it did make me curious.

Just came back from the garage where I loaded 5 rds with just one piece of brass in the shell holder at a time.  The AOL ranged from 1.148" to 1.152".

I also measured 5 random rds from a batch I reloaded  this past weekend. They ranged from 1.149" to 1.151".

So no real change.

I'm using  a 550 that went through the Dillon factory for refurbishing  last Winter, Dillon dies and Hornady lock rings.

[AzShooter]

Make sure your tool head is tight.  If it's not you will get variances.  Also, make sure you shell plate is tight.  You can make a small shim for the tool head.  Just tighten down the shell plate to where it moves freely but you don't see cases moving  up and down.

[ams30gts]

Shadowing above.  Make sure the toolhead and shell plate are tight enough.  Also make 100% sure you are doing full strokes.

[GrumpyOne]

You should set up a progressive press with all stations full. With only 1 station with brass in it, the shell plate, if loose enough to turn, which it has to be, will move up and down those few thousandths that you are finding. Re-adjust your press with a full shell plate and your variances will go away.

[rustybayonet]

Shell plate on a 550 is not to critical, since the case base is against the ram. What I do is set everything with one round ran thru all four stations, then I do a tweak to the stations with all stations full. The toolhead even if loose will only rise to a set point. The case base will always be at the same position as long as the ram is in the same position. When you have one round in the press the slop in the toolhead may cause it to tilt and change the OAL. If you can shim the toolhead you should be able to get the single round and full press OAL constant. On my 550 the differance is +/- .02 OAL at worst.

[VIPERONE]

I have always used the Dillon Lock Rings. I am starting to change them out to the newer 1" ones. Way handier for adjustments.

Bob

[SCTaylor]

1 hour ago, GrumpyOne said:

You should set up a progressive press with all stations full. With only 1 station with brass in it, the shell plate, if loose enough to turn, which it has to be, will move up and down those few thousandths that you are finding. Re-adjust your press with a full shell plate and your variances will go away.

Every time I forget to do this, it drives me nuts. Grumpy is right, as ::cough:: always!

[Hi-Power Jack]

I seem to recall an incident, about nine years ago, when Grumpy was, ever so slightly,

not quite "right" ...   

But, I might be incorrect ....  

Matter of fact, I'm pretty sure I am incorrect .... 

[Sarge]

Shell plate being tight is indeed critical for consistency.

[GrumpyOne]

7 hours ago, SCTaylor said:

Every time I forget to do this, it drives me nuts. Grumpy is right, as ::cough:: always!

Not always...I thought I was wrong once...but I was mistaken.

[9x45]

9 hours ago, rustybayonet said:

 On my 550 the differance is +/- .02 OAL at worst.

Don't you mean +/- .002" ? as in two thousandths and not as in twenty thousandths....

OP, all stations have to be full for OAL and de-bell (crimp) because the pressure is much less with only one round on station.

[Angrysquirrel]

Thanks to everyone who replied. When I read Grumpy's response I gave myself a face palm.  

I will readjust. 

By the way this press is awsome. I wish I would have bought this 6 years ago rather than the ones I just sold. Oh well, had to start somewhere, because of my original press I really appreciate my new Dillon!

[rustybayonet]

3 hours ago, Sarge said:

Shell plate being tight is indeed critical for consistency.

Shell plate on a 550 is only critical for primer depth. The round is between ram and seating die. At station 3 the plate just keeps the round lined up with the die. I keep mine loose enough to move easy, but tight enough to seat the primer a the correct depth.

[benos]

21 hours ago, 9x45 said:

OP, all stations have to be full for OAL and de-bell (crimp) because the pressure is much less with only one round on station.

That. In addition, with only one round in the Shellplate, that round will tip the Toolhead at an angle, as opposed to a fully loaded Shellplate, that will load the Toolhead up evenly in the press's frame.