Load Variation in a Dillon

[metallurgist]

I've discussed the variation of loads in a Dillon with a couple friends lately. That got me to wondering about testing just how much mine vary.

Then in perfect timing, one of the articles in Dillon Precision's latest catalog was explaining a test they performed on comparing powder charge weights from their powder measure to other methods.

I decided that I'm going to put together a series of 3 different tests looking at the variation in powder, case sizing, seating, etc., and how that relates to performance.

This is the first test which is about powder charges, and I'll update as I complete the other two. I compared some of Dillon's data to my own in the video, and I made an attempt to translate that into variations in POI based on powder only.

 

[FishDr]

Interesting results. I'm in for a watch.
How many rounds have you loaded on that Dillon? It looks well loved. Also, there are a number of mods which you can do to the powder drop to make it more consistent. Add to that, there are certain techniques/methods for operating the press which can also help decrease the variation in charge weight. Search for the dillon powder drop modifications - they were very helpful on my setup.

 

[metallurgist]

Interesting results. I'm in for a watch.
How many rounds have you loaded on that Dillon? It looks well loved. Also, there are a number of mods which you can do to the powder drop to make it more consistent. Add to that, there are certain techniques/methods for operating the press which can also help decrease the variation in charge weight. Search for the dillon powder drop modifications - they were very helpful on my setup.

Thanks!

It's had its share of use. I bought it about 15 years ago from my cousin, and I have no idea how long he had it before then and how many rounds he went through. They're a great machine to hold up that well for so long.

I've been looking up powder mods since you've mentioned it, thanks for that recommendation. I'd seen many other Dillon mods, but not those for the powder until I specifically looked for those.

I'm testing out a couple other things at the moment and will wrap them up in the next video, then I think I'll try these mods and retest my variation.

 

[FishDr]

I'm testing out a couple other things at the moment and will wrap them up in the next video, then I think I'll try these mods and retest my variation

That will be most interesting. Cant wait to see how it comes out.

 

[bghartm]

Watching this too. I have been contemplating buying a Hornady Lock N Load case activated powder drop or Unique tek parts to replace Dillon.

 

[metallurgist]

I also wanted to test my headspace variation in addition to brass weights before I get into the live fire with real velocity data so that I can try to bring them all together and see what does what.

I had wayy more variation in headspace than I expected. A standard deviation of about 0.002" on that.

Brass weights varied how I expected.

This video is my results. Next video will have velocity data, then I'll get back to seeing if I can reduce the powder variation.

 

[FishDr]

I posted this on another thread, but looks like it would help here as well. Put an extra powder die in the station directly across from your FL resizing die. Set it to barely kiss the shell plate at full raise of the ram. THEN set up your FL sizing die across from it. This will balance the forces on the shell plate and help make the shoulder bump much more consistent.

Another item to consider is a small "dwell" at the top of stroke. I don't know that it helps a lot, but doesn't hurt. I seem to have pretty consistent shoulder bump. Good lube / consistent lube is also important. Beyond that, you could try any of the mods that make the tool head solid; but my experience has been that the above solves any issues and the special tool heads aren't necessarily needed.

 

[mercracing]

I posted this on another thread, but looks like it would help here as well. Put an extra powder die in the station directly across from your FL resizing die. Set it to barely kiss the shell plate at full raise of the ram. THEN set up your FL sizing die across from it. This will balance the forces on the shell plate and help make the shoulder bump much more consistent.

Another item to consider is a small "dwell" at the top of stroke. I don't know that it helps a lot, but doesn't hurt. I seem to have pretty consistent shoulder bump. Good lube / consistent lube is also important. Beyond that, you could try any of the mods that make the tool head solid; but my experience has been that the above solves any issues and the special tool heads aren't necessarily needed.

do you only put one die in across from the FL die, or is it better to fill all the spots not being used?

 

[FishDr]

I use all four (five on the 650). At minimum, I would put an empty powder die across from the FL die. Here is my setup for the 550 to process:
1. Universal decap
2. FL size with expander removed
3. Neck expanding mandrel
4. Powder die (empty)

 

[mercracing]

@FishDr, thanks for the reply, I was thinking about getting an extra powder die or universal decaping die( pin removed of course) to take up the extra spots on the two heads I’ll use for my 6CM.

 

[flyright]

Weight sorting of brass does not directly correlate to case volume. I know several benchrest shooters who volume sort cases using alcohol, water or some other liquid, to fill the case then weigh the difference with the liquid. They've told me that just weighing the brass won't tell you much. They use only the best quality brass that has very little weight deviation to begin with.

The better quality brass also shows less deviation in sizing. I've found this to be true and shooters who anneal and those that don't both agree. I believe it's due to better metallurgy. Those weird pieces of brass that either won't setback or setback too much with the same die setting get culled - at least by BR shooters. Headspace variation of .001-.002 can be caused by a difference in metallurgy or even differing amounts of lube and with any type of press - coax, single or progressives. Luckily, it doesn't seem to make any difference on paper according to the BR guys and that's good enough for me.

A couple of my BR shooting friends keep 20-30 pieces of brass set aside that they shoot "for score" and the other 200-300 or so pieces are for practice. So, only about 10% of that highest quality brass is good enough for their purpose. There are a whole lot of variables and rabbit holes in reloading but that's half the fun. Thank you for the videos!

 

[metallurgist]

I posted this on another thread, but looks like it would help here as well. Put an extra powder die in the station directly across from your FL resizing die. Set it to barely kiss the shell plate at full raise of the ram. THEN set up your FL sizing die across from it. This will balance the forces on the shell plate and help make the shoulder bump much more consistent.

Another item to consider is a small "dwell" at the top of stroke. I don't know that it helps a lot, but doesn't hurt. I seem to have pretty consistent shoulder bump. Good lube / consistent lube is also important. Beyond that, you could try any of the mods that make the tool head solid; but my experience has been that the above solves any issues and the special tool heads aren't necessarily needed.

That's excellent advice, thank you! I didn't think of that, so I'll have to try that out.

I noticed somewhere that they made threaded inserts and bolts to replace the toolhead pins and keep the head pegged to the top of the press. I'm curious, though, about the center bolt that holds down the shell plate. Without any brass in it, raising my ram to the top of the stroke, I was noticing some movement in the toolhead. So watching it even closer, it looks like the center bolt fits into the center hole of the tool head and pushes it up against the top of the gap. It even looks like it was designed to do that because the chamfer on both looks made to match. I'm curious if any of you have noticed that, too? Or maybe I just have that set up very poorly!

Weight sorting of brass does not directly correlate to case volume. I know several benchrest shooters who volume sort cases using alcohol, water or some other liquid, to fill the case then weigh the difference with the liquid. They've told me that just weighing the brass won't tell you much. They use only the best quality brass that has very little weight deviation to begin with.

The better quality brass also shows less deviation in sizing. I've found this to be true and shooters who anneal and those that don't both agree. I believe it's due to better metallurgy. Those weird pieces of brass that either won't setback or setback too much with the same die setting get culled - at least by BR shooters. Headspace variation of .001-.002 can be caused by a difference in metallurgy or even differing amounts of lube and with any type of press - coax, single or progressives. Luckily, it doesn't seem to make any difference on paper according to the BR guys and that's good enough for me.

A couple of my BR shooting friends keep 20-30 pieces of brass set aside that they shoot "for score" and the other 200-300 or so pieces are for practice. So, only about 10% of that highest quality brass is good enough for their purpose. There are a whole lot of variables and rabbit holes in reloading but that's half the fun. Thank you for the videos!

Very interesting! So hopefully it won't matter enough with the fired results to have to worry about it too much then. My concern was that out of a 100 round lot, if I have to split it up into 3 or 4 groups, then I'm going to be limited to how much actually matches.

 

[Gustav7]

I came across this article a dude wrote at some point in history about accurizing his Dillon 550 to perform better. I've done a few of those.

I like the idea of the empty die opposite of the sizing die.

I'm also in the two toolhead group... although I do want to test all on one toolhead with the Dillon powder measure.

 

[biffj]

When you get done with all this testing you might try testing the variation in the powder drop from a full powder measure to the baffle as you empty it out. I see a lot of change as the powder level drops and find that I'm still weighing about every other charge in stuff I care about just to make sure. The baffle helps but its not a fix. The variation changes a lot depending on the powder too. XBR8208 for the 6.5 Grendel is much more consistent than 4831 for the 7.92 Kurz.....

Frank

 

[rjz5400]

i found the mods to my powder measure, funnels, and hopper to be very useful in keeping the powder flakes down from leakage and hangups and also to improve consistency by a lot.

I am mostly loading bulk ammo for 3gun on my 650 but i also load my "long range" 75 gr bullets on it for longer stages. i found deviations were smaller than my beam scale could even measure. like a kernel or two between charges. I do random sampling every few minutes as I load.

 

[rjz5400]

There is guy on youtube has a longer video about polishing, using a dryer sheet for storage, an anti-static grounding wire. and using graphite as a dry lube when getting setup.

 

[smoothy8500]

I do my 223 "match" ammo on a progressive too. I find a node where the vertical dispersion and accuracy are stable within the +/- range of the powder dropper. At 600yds or less distance, the ES/SD is not affecting accuracy.

 

[metallurgist]

When you get done with all this testing you might try testing the variation in the powder drop from a full powder measure to the baffle as you empty it out. I see a lot of change as the powder level drops and find that I'm still weighing about every other charge in stuff I care about just to make sure. The baffle helps but its not a fix. The variation changes a lot depending on the powder too. XBR8208 for the 6.5 Grendel is much more consistent than 4831 for the 7.92 Kurz.....

Frank

Yeah, that's one of them on my docket to test. If baffles make a difference, then it would only make sense that powder weight affects the flow and fill.

There is guy on youtube has a longer video about polishing, using a dryer sheet for storage, an anti-static grounding wire. and using graphite as a dry lube when getting setup.

Do you know if he says what kind of variation he gets? In theory, doing what you can on all of that adds up, but I'm just wondering if it turns out to make a real difference?

I do my 223 "match" ammo on a progressive too. I find a node where the vertical dispersion and accuracy are stable within the +/- range of the powder dropper. At 600yds or less distance, the ES/SD is not affecting accuracy.

That's what I'm after here ultimately. Are you using a rod powder or something else? And do you know what kind of variation you're getting in your powder weights?

 

[rjz5400]

When I did all the "mods" it was really to address bridging and sticking, or leakage after the case had moved down and rotated. The main video I used was for leakage/spillage

The side effect was smoother and thus more consistent powder drops. It was/is more than good enough for my 100 yard 3gun targets.

 

[smoothy8500]

That's what I'm after here ultimately. Are you using a rod powder or something else? And do you know what kind of variation you're getting in your powder weights?

I'm not using a Dillon, instead, it's an older Hornady dropper. Ball powder (AA2520/W296) is within .1grain and even the longest stick powders such IMR 4064 are +/- .2 grain. Find your node that the velocity shows a plateau, and more importantly, vertical dispersion is minimal.

Your video over-all was pretty good, but a couple of minor things to consider is that increasing load doesn't always equate to velocity increase (the plateau). Also, the velocity differences don't always equate to changes in POI. Consider that some stable velocity test loads (low ES/SD) will still show a terrible 10 round group.

Do the mods to your Dillon (polishing, baffle, etc) and find the optimum charge weight to have decent accuracy within that range.

 

[metallurgist]

I'm not using a Dillon, instead, it's an older Hornady dropper. Ball powder (AA2520/W296) is within .1grain and even the longest stick powders such IMR 4064 are +/- .2 grain. Find your node that the velocity shows a plateau, and more importantly, vertical dispersion is minimal.

Your video over-all was pretty good, but a couple of minor things to consider is that increasing load doesn't always equate to velocity increase (the plateau). Also, the velocity differences don't always equate to changes in POI. Consider that some stable velocity test loads (low ES/SD) will still show a terrible 10 round group.

Do the mods to your Dillon (polishing, baffle, etc) and find the optimum charge weight to have decent accuracy within that range.

Just to make sure I'm understanding what you're saying, test a range of powder charges to find a plateau in corresponding velocities?

 

[smoothy8500]

In a nutshell, yes. Whether using test methods such as OCW optimum charge weight, Satterlee's ladder test or another. That way your load is fine even if the charges are not exact, it's still in the accurate range of charges. Slight variations don't affect accuracy or POI. This is true up to 600yds.

 

[smoothy8500]

Look up OCW or Satterlee for more info or alternative methods to find accurate nodes. Even straight up velocity plateau with good accuracy will work. Others may have a method that finds an accurate node and you can crank out great ammo on the progressive.

 

[metallurgist]

Finally getting to the live-fired velocity results.

Video starts a little slow, so bear with me as I worked through the background.

Overall, I definitely need to be getting the powder drops dialed in. That variation was so large that it was difficult to see effects from the other factors.

My standard deviation of my powder drops was still in the 0.17-0.18 grains range, and my test showed about 5-6 fps difference per 0.1 grains.

My goal right now is to get my SD to less than 0.1 grains. If I can get that dialed in, I'll move on to the next pieces.

 

[metallurgist]

Okay, a little more excitement with how this turned out. I think this is what most people might be interested in.

I tested out a baffle, vibration, grounding, and polishing. All 4 combined gave me a 23% reduction in my standard deviation, and my extreme spread of powder drops was cut almost in half.

I put this into more of a how-to format to show kinda what I did for each and what the results were.

 

[metallurgist]

So I wanted to figure out just how consistent I could get with testing to a node, loading to that node from the Dillon powder measure (with previous improvements), and then firing for a group size. Basically, is the Dillon powder measure consistent enough at a node for good groups? I'd say that I was able to get to Sub-MOA fairly confidently with that.

 

[flyright]

You might try 41.5 and 42.5, pretty solid velocity numbers and different nodes only 100fps apart. If you can assure +/- .2 grain powder split it should be pretty good for MOA or better out to 600 yds or so. When velocity decreases with an increased powder charge; I know something is amiss or I'm on/past a node. Neck tension/bullet grip can exacerbate velocity spreads too. Also, be sure that vertical error is not shooter induced. Tweak your bullet set depth and you're going good. Thanks for the videos! Just my .02.

 

[metallurgist]

You might try 41.5 and 42.5, pretty solid velocity numbers and different nodes only 100fps apart. If you can assure +/- .2 grain powder split it should be pretty good for MOA or better out to 600 yds or so. When velocity decreases with an increased powder charge; I know something is amiss or I'm on/past a node. Neck tension/bullet grip can exacerbate velocity spreads too. Also, be sure that vertical error is not shooter induced. Tweak your bullet set depth and you're going good. Thanks for the videos! Just my .02.

Thanks!

Yeah, I wasn't sure if it was the chrono on those or node effects. I've got a LabRadar on my wishlist!

Some of the vertical error on that was definitely me. I knew as soon as I fired that I had pulled it and sure enough.

I've been annealing my brass after each firing, but I'm new enough to doing that to where I'm not sure about how to adjust my anneal for proper neck tension...yet.