Questions about RL550B


June 12, 2011, 12:30 PM
As some of you know I got a smoking deal on a RL550B at a garage sale on Friday while working up in Duluth. $55 for the press still in the box unopened and a 9mm Caliber Conversion kit. I set the press up Friday night. I decided to run a few rounds and see how it would shake out. Since I have been doing all my reloading on a single stage I would size a bunch of cases, bell a bunch of case, prime a bunch of cases and load. I have about 600 cases primed ready for powder and a bullet. I decided to run 100 through the press that were already primed, I just skipped the first station. That went great after I got my powder amount dialed in.

Saturday morning I decided to run 100 rounds from start to finish. I loaded up the primer tube with 100 Winchester small pistol primers. The hopper with Power Pistol and I grabbed 100 once reloaded Federal brass. I was having a lot of trouble getting the primers to feed from the tube to the part that catches it and slides back under the case to install it. I did some searching on the net and found I had the screws to tight and I adjusted the rod a little. At this point everything is going great and then BANG. *** I just had a primer go off in station #1. I pulled the case off and there isnít a dent in it, it looks like it went in straight and right side up. I donít know how the heck it happened. I didnít think a primer going off would be that loud and I got the are you alive hauler from the wife up stairs. Do you guys have any ideas why this happened and is this a common thing with a progressive press? I would guess I have loaded 5000 rounds with a hand primmer and I never had a primmer go off.

When I started reloading I bought a RCBS dies. In the setup instructions for the belling die, it just says to flare out the case just enough to get the bullet started. I have flared to the point that I had to push the bullet to get it to sit in the case. The Dillon instructions show a few pictures and say you want 0.020Ē size difference from a case that hasnít been flared. When setting up I got the flare out to 0.018Ē and decided not to mess with it anymore. The case is way more flared out than I ever did with my single stage press. So was I under flaring all this time or am I flaring it to much now.

All the rounds I have loaded with my single stage press to this point have functioned great. I have always wondered if my crimp is correct. In the instructions from my dies, they say you want the crimp to be 0.005-0.010Ē smaller then measurement on other parts of the case. What part do I measure from on the case. Right now if I measure the crimp compared to the other end of the case I am at about 0.010Ē smaller at the crimp. As I move closer to the crimp that number gets smaller. Am I doing this right?

I remember reading not to leave powder in my RCBS powder thrower because it can eat the plastic. I didnít see anything about that in my Dillon instructions. Right now I am using Power Pistol for 147g and W231 for my 115g. Is it alright to leave either one of these powders in the hopper or should I empty it after every reloading session? Is there anything else you guys suggest I get for my press that doesnít come in the box.
Any other tips you guys can give me on the 550 and progressive presses in general would be great. I also found if you donít put the little brass pin back in place after checking a powder charge, the case really gets jacked up when you pull the handle.


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June 12, 2011, 03:22 PM
Don't leave powder in the measure. It may or may not "eat" the plastic, but it will stain it. Disconnect the tie rod that attaches the powder measure to the shell plate assembly, pull the 2 pins holding the toolhead and remove the toolhead with the powder measure in place. Use a funnel and pour the powder back in it's container, then turn it right side up and work the powder measure by hand a few times over the funnel to get all the powder out. Reinstall the toolhead and write the load and powder charge you were using on a piece of paper and put it in the measure so you can read it through the plastic you just saved from permanent staining.

June 12, 2011, 03:36 PM
I don't have a clue how you managed to detonate a primer, I've completely crushed/deformed several primers trying to seat them in crimped brass that slipped by when I swaged them without an incident. Long as it happens slowly they seem to be pretty stable. I've heard of a lot of detonations in 650's for some reason, but not 550's. I'm sure someone has seen it and knows what causes it though.

As for equipment, if you don't have the dillon strong mount and the roller handle, I would suggest them if you load high volume or long periods of time. If the machine is mounted by itself on a standard height table/bench, the strong mount will raise it up to a surprisingly easy-to-use height.

June 12, 2011, 03:47 PM
The only trouble I've had with the RL550B primer system was

1. I wore out or broke the "Flexible Orifice" (plastic fingers) on the end of the primer tube on the press. This part is the key to how the primer slide picks up a new primer. Dillon sent me a new one for free.

2. I didn't have the shellplate properly adjusted and I was getting "crooked" primers. They never went off, but they weren't straight. The shellplate has to be snug as the case bears on it during priming.
I'm not sure I understand your crimp measurements. Rimless semi-auto cartridge cases are usually belled just enough to support a bullet (and prevent shaving) and then the taper crimp die is adjusted to remove that bell completely. There isn't a visible crimp in any of my .45ACP rounds.

Regarding storing powder in the powder measure, I've done it for a week or so without incident. Whatever plastic Dillon uses doesn't seem to react with Bullseye, Varget or H110. There is no discoloration whatsoever. However, other powders may behave differently and there really isn't any reason not to dump the powder back into its container between sessions. If you don't have a dedicated powder measure for each tool head, this is probably a safer practice as well, as it should make mixing powder types less likely.

Jim Watson
June 12, 2011, 04:05 PM
I don't know how you managed to pop a primer. Are you sure you have the small primer cup in place? Does the cup come up through the hole in the shellplate without snagging?

I often leave HP38 (same as 231) powder in the measure with only a little discoloration.
BUT NOT Power Pistol it will chew the dickens out of the cheap acrylic they make hoppers out of. Lots of nitroglycerine? Residual acetone-ether-alcohol solvent? I dunno but it will attack the plastic.

Did you get the instruction manual?
Even if you did, Dillon is very good with phone help. Got a problem? Call 'em up.

June 12, 2011, 04:17 PM
I permanently stained mine by leaving Ramshot Tac in it for quite a while. Don't remember how long, but I have tried scrubbing the stain out it won't budge.

June 12, 2011, 05:20 PM
Thanks everyone for the advice. Yes I got the manual and I did switch over to the small primer system.

June 12, 2011, 06:57 PM
The rule for belling on any press is the minimum you can get away with. You should not be slicing any samples off the bullets during seating. So the size flare depends on the type and brand of bullets you're seating, not the type of press. I've seated Berry plated bullets with zero flare, while lead bullets usually take the most.

Taper crimp is an exercise to erase the flare so that the round will drop into your chamber. So dropping successive test rounds into your naked chamber will tell you when you have enough TC. See the dimension .380" at the case mouth in your manual? Your finished cartridge will probably finish out ever so slightly less than that, say .378".

There are numerous tiny adjustments to make on a 550. These are 1 time adjustments and once they are set, you're good to go. The hair-pin spring on the #1 position should barely touch the case. The socket head screw holding the primer bar out. The location of the shell supporting plate, so that the primer come up perfectly through the hole. It's all detailed in the manual.

Hondo 60
June 12, 2011, 09:20 PM
Sorry but I too can't say why your primer popped.

I usually load a box here & there, so I leave the powder in the dispenser.
That's not a good thing to do.
My 550 is 10 months old & the powder dispenser is very darkened.

I've found that I have primer issues when I tighten the knurled Primer Shield Cap too tight.
I hand tighten it & then back it off a quarter turn to leave it just a bit loose.

June 12, 2011, 10:15 PM
I just spent some time in basement running through some scenarios of what could have happened. Here is what I think may have happened. Resize/de-prime a case, without a new primmer in the primmer cup push the handle forward as if I had a primmer in the primmer cup. I did this on multiple cases, a few times the deal that comes up and pushes the primmer would shave some brass inside the primmer pocket. When this happened the brass would not fall out because it was still connected to the inside of the primmer pocket. The primmer that went off, I took it out of the case. Two out of the three legs are depressed. My memory of what happened right before that primmer went off isnít there probably because the primmer going off scared the hell out of me. Before the primmer went off I was still having some problems with primers not falling into the cup when I would stroke the press. When that would happen I would feel it when I went to set the primmer. I would look through the case and see there wasnít a primmer and manually pull the bar back and make sure there was a primmer in the cup and then set it. So I think I tried to prime a case with no primmer, notice the different feel, manually got a primmer in the cup, went to prime the case and bang it went off. After it went off I would visually check the primer cup as it is coming back to the priming position. I will continue to do that from now on.
Thank you everyone for your advice and thoughts on this.

June 12, 2011, 10:51 PM
Primers don't fall for 2 reasons....

• The primer tube needs a cleaning swab run though it just like a gun barrel. Put a clean patch or 2 on a piece of straight coat hanger wire and give it a swab. No oil required.

• You haven't got the black plastic primer rod in place like this....

That added weight of the rod insures that the primers feed well.

June 12, 2011, 11:08 PM
Primers don't fall for 2 reasons....

• The primer tube needs a cleaning swab run though it just like a gun barrel. Put a clean patch or 2 on a piece of straight coat hanger wire and give it a swab. No oil required.

• You haven't got the black plastic primer rod in place like this....

That added weight of the rod insures that the primers feed well.
I figured out why the primers weren't going into the primmer cup everytime. The bar wasn't coming back far enough to push in the white tab and catch the primmer.

June 14, 2011, 10:46 AM
An update. I sent Dillon an email last night explaining what happened and how I thought it may have happened. I got a response from them today. In the email they asked that I call them, they had some more questions and thought it would be easier to talk over the phone. I called them on my lunch break and here is how it shook out. They are sending me a new primmer cup and some other parts that are part of the primer loading system. With those parts will be a prepaid box so I can send them the parts off my machine back. He said they would like to take a look at them because a year or so ago they had some bad parts go out with some 550B presses. He said he thought they had caught almost all of them before they hit the stores. He also made the comment he hoped they didn’t get a string of back parts that made it through QC again. I came clean and told him about buying it at a garage sale for $50 and that the box was unopened. His comment to that was I got a killer deal and they will still stand behind there product. After talking to him I decided I am going to hand prime until I get the new parts in the press.

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