How to improve powder dispensing in a 550

lately I have ignored my 45 and shot a lot of 38spl in my SW52.  I was cronographing the difference between
plated HBWC and lead HWBC with the same powder load:  the plated give at least 50fps more than  the lead.
Not a surprise. Then comes along a 500 fps and a 550 fps in the groups of 10 or so from the lead.    My usual speeds with2.7gr of 231 is 675 to 725, with the occasional
785.
It is either the loader person  or the 550's powder dump is not consistent. I thought of a vibrator for the powder
hopper, and a friend uses produce rubber bands to snap the powder tray back in place.  I see where some have a weight on top of the powder- what's the best solution?

My Dillon powder measures are fairly accurate but I have the extra small powder bar in all my powder measures and Dillon sells a return spring for the powder bar that shakes things up fairly good. I also keep the powder hopper over Half full when loading so I get even powder flow.

My 550 has been good for 38 hbwc. I use bullseye.

Hiya,

Do you have the "extra small powder bar" or just the standard small bar that comes with the measure? I found that the standard small bar is very inconsistent below 3g with flake powders. That being said, the Dillon measure need at least 50 cycles to settle in and reach its best consistency. It's not the best measure if your making 20 round test lots but it's reasonable if your loading 500 or so.

Also, the threads on the adjusting screw are UNC 1/4x20 so a little turn equals a big change, especially with the standard small bar as the bar opening is tapered at the end. Another thing I do to set the drop at the right amount is do 20 drops then divide that by 20 to get the average drop weight. By increasing the total weight you eliminate the 1/10th grain tolerance that most scales have and when you're dealing with 2.5g charges, 1/10th is a big deal and most scales can't tell you if you're at 2.49 or 2.59g.

extra small powder bar on the way.

^What Tom said, had the same issues with 38 special loads.  Small bar made a huge difference.

There is also a slightly thicker spacer available for the powder bar that tightens things up. I was having a slight leakage problem with Titewad.

Had similar issues till I switched to the extra small powder bar. Now very consistent with 2.7gr WST. Worked great with N310 and 1.8gr during my brief .32 ACP experiment.

I will be ordering the extra small bar also.
Today I removed the small bar to dial down my powder drop to minimum and got a 2.7 drop of bullseye.
Didn't try 321 yet. But the small bar only had a slim triangle void for powder to fill.

L. Boscoe wrote:lately I have ignored my 45 and shot a lot of 38spl in my SW52.  I was cronographing the difference between
plated HBWC and lead HWBC with the same powder load:  the plated give at least 50fps more than  the lead.
Not a surprise. Then comes along a 500 fps and a 550 fps in the groups of 10 or so from the lead.    My usual speeds with2.7gr of 231 is 675 to 725, with the occasional
785.
It is either the loader person  or the 550's powder dump is not consistent. I thought of a vibrator for the powder
hopper, and a friend uses produce rubber bands to snap the powder tray back in place.  I see where some have a weight on top of the powder- what's the best solution?

I have never had a problem with Dillon powder measures being inaccurate. I see that you think that yours is inaccurate based upon velocities. Have you done any machine rest tests at 50 yards to see if it affects your accuracy? Do you think that your velocity differences could be because of other factors, i.e. bullet, consistency of bullet seating, consistency of crimp, etc.?

I have both the 550b and 550c. It appears that Dillon responded to powder drop issues by redesigning the powder bar actuator by adding a "shaker" modification. It's a slight bend in the bell crank that snaps the bar to shake the dispenser. 
Some new owners thought this was a defect and straightened this out! This has been discussed on other threads.
Check to see which model you have and that it hasn't been "field modified"! "B" models that get repaired get the new "C" model  bell crank I'm told!

I have the mod.

Some people use vibration to help get powder charge uniformity.

To funny

Wobbley wrote:Some people use vibration to help get powder charge uniformity.

sorry to be asking, for real?

Internet picture…so make up your own mind.

BUT…it is common on dry bulk hoppers and rail cars like these

This is to empty grain cars, but it allows granular things to move. So the theory is sound. Some of these things are adjustable for speed or intensity so???

I just thought it was funny!

I haven't tried it but have read about strapping an inexpensive aquarium air pump to the powder measure would help with charge uniformity.
Darrell

Sorry, but Star owners are laughing to themselves about this discussion topic.

rbwillnj wrote:Sorry, but Star owners are laughing to themselves about this discussion topic.

Bruce,
As a Star owner, I hear what you are trying to say, and as well what you don't.  And that would be topic for another discussion.  Yes, Star presses have two major advantages in comparison with Dillon's or any other progressive press on the marker regardless of the powder measure type they use.  Very specifically, Star presses 
1. do not have case activation mechanism, and hence are not susceptible to case length variations;
2. have shell plate that functions as just a rotator of cases, while cases bases seat on solid base as opposed to wobbley (no pan intended, Ashley!) shell plates on other progressives, that are affected by pressures from each die on each station.   
However accuracy of powder charges on Star presses (powder hoppers and powder bars) are affected by same "Silo effect" as all others.

Now, as a Dillon owner I can state that my Dillon presses hold same accuracy of powder charges (+/- 0.04gr. with most powders) as my Star presses.  Yes, it took a bit more effort to tune Dillons then Stars.  And that includes designing and machining several replacement parts and modifying powder bars (see picture).  However it is possible.  On a flip side Dillons offer more functionality and versatility in comparison with Stars.  However that's topic for different discussion.



AP

PhotoEscape wrote:

rbwillnj wrote:Sorry, but Star owners are laughing to themselves about this discussion topic.

Bruce,
As a Star owner, I hear what you are trying to say, and as well what you don't.  And that would be topic for another discussion.  Yes, Star presses have two major advantages in comparison with Dillon's or any other progressive press on the marker regardless of the powder measure type they use.  Very specifically, Star presses 
1. do not have case activation mechanism, and hence are not susceptible to case length variations;
2. have shell plate that functions as just a rotator of cases, while cases bases seat on solid base as opposed to wobbley (no pan intended, Ashley!) shell plates on other progressives, that are affected by pressures from each die on each station.   
However accuracy of powder charges on Star presses (powder hoppers and powder bars) are affected by same "Silo effect" as all others.

Now, as a Dillon owner I can state that my Dillon presses hold same accuracy of powder charges (+/- 0.04gr. with most powders) as my Star presses.  Yes, it took a bit more effort to tune Dillons then Stars.  And that includes designing and machining several replacement parts and modifying powder bars (see picture).  However it is possible.  On a flip side Dillons offer more functionality and versatility in comparison with Stars.  However that's topic for different discussion.



AP

OK, I see the circles on the photo but cannot discern exactly what you did and why.  Please expound.

Dennis, aka Dulmrman

Dulcmrman wrote:OK, I see the circles on the photo but cannot discern exactly what you did and why.  Please expound.

Dennis, aka Dulmrman

I don't want to write long essay on the subject, - issue with accuracy and consistency of powder charges on any press can add up to PHD Dissertation.  So, I'll try to be brief and limit answer to just how powder bars affect accuracy.

First picture for the illustration - 00 Powder Bar for Star Press with FIXED cavity rated for 2.9gr of BE, on top of it Replaceable bushing with cavity rated 2.65gr of BE for  for Powder bar that allows replacement of bushings, and above you can see an empty bag from another Replaceable bushing that is rated for 2.75gr of BE (this one is installed on one of my Star's).  As you can see all cavities have fixed dimensions and do not allow for adjustments.  There are pros and cons in this.  Obvious advantage is that volume of powder that goes into cavity is always the same (I'll omit here Silo effect).  Obvious disadvantage is that .......... volume of powder that goes into cavity is always the same.  Yes, inherited accuracy of the powder charge due to constant size of the cavity on one end, and inconvenience of not being able to adjust powder charge on another end without replacing entire powder bar or bushing.  There are two additional points worth noting.  One - Rating of the cavities is not the same for different lots of the same powder.  It can be 2.9gr for lot A, 2.85gr for lot B, and something else for lot C.  Two - Powder bars with adjustable cavities are available from Star / Bruce, and they are better made than Dillon's. 



I will continue on the next post.

AP

This picture represents modified Small Powder bar for Dillon's platform.  Pretty much all Dillon's presses use this version nowadays.  Modifications include replacing adjuster bolt with my own, and installing set screw.  If you take OEM bar in one hand and use your fingers trying to move insert of the bar back and force, you will notice substantial backlash.  The reason behind is loose threads on the bolts.  Dillon economizes on this part by using stamped bolts.  Referenced backlash creates +/- 0.1+gr on small and +/-0.2+gr on large bar difference in powder charges.  My bolts are machined with full threads, and practically eliminate backlash.  However, in addition to that I install set screws and lock insert once I settle on powder charge.  In essence now my bars have fixed cavity like those on Star, and yet still adjustable when necessary.  Also two additional points worth mentioning.  One - as I wrote in the first post on this thread, variations of charges come from multiple components of the press.  As it pertains to powder bars, flow of the powder into the cavity depends on level of powder in the hopper, jolts produced be returning mechanism of the powder measure, reloader itself operating lever  - just to name few.  Hence it is advisable to check charges every so often, especially during longer loads.  Two - you must remember to unlock insert before making adjustments.

AP

Thanks for posting both of these.  You've given me a lot of useful thoughtful ideas.

Dennis, aka Dulcmrman

I have a Square Deal B set up for 38 Special with an extra small powder bar. I like to have a rubberband on the powder bar to help it move. I also electrically ground my presses to drain any static electricity. I put a piece of tape on the powder tube to mark a 2 inch range of "head pressure". Last I have a Prairie Dog Powder Baffle in the powder hopper.

With all this I get ten powder drops that weigh where I want them (28.0 for ten drops).

Sa-tevp wrote:... I also electrically ground my presses to drain any static electricity...

Can you please share a photo of how you electrically ground the press (or explain how)? Thanks in advance