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Old June 26, 2011, 01:03 PM   #1
tobnpr
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Adapting an electronic scale/dispenser to a progressive press?

I currently use a Hornady LNL Progressive with the powder drop.
I'm considering getting an electronic scale/dispenser, and somehow adapting a gravity feed tube to get the charge into the shell at the station on the press where the powder drop is now located.

Has anyone tried to do something like this?
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Old June 26, 2011, 02:20 PM   #2
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With every auto dispenser scale I've seen the cycle ends with a measured charge in a pan on the scale. Trick will be to move the powder from the pan to a drop tube leading to a case at the appropriate time. Not saying it can't be done but I have every confidence in a good quality powder measure. The Dillon measure on my 550 is probably very close to my RCBS Chargemaster as far as accuracy is concerned.
Rumor has it that volume is more important than weight, if that's true there's nothing to be gained by this adaptation but I'm looking forward to the pics (video?) posted by the guy who has pulled it off!
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Old June 26, 2011, 02:35 PM   #3
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Exactly.
It's the volume issue I'm trying to solve.
I'm going to "beef up" my reloading table so it doesn't vibrate/move so much when I size the cases.

It's this vibration, I believe, that's causing the inconsistency when I meter Varget. Since it's an extruded powder, it doesn't pack tightly in the powder drop measure- and excessive vibration (I think) causes overcharges of up to half a grain sometimes. The ball powders meter very accurately, so I'm guessing this is the issue.

Hopefully beefing up the table will help, if not this seemed like an interesting idea if practical.
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Old June 26, 2011, 03:54 PM   #4
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I'm thinking vibration could be a factor here but disagree on the solution. I'm wondering if a couple of taps to the base of the measure before each throw could help settle the powder for a more consistent throw. I avoid stick powder in a measure because of the "bridging' issue but some folks make it work, obviously.
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Old June 26, 2011, 04:35 PM   #5
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Stick powders are harder to meter, but are also typically less sensitive to exact charge weight. The thinking is that when they pack tighter it obstructs the flow of flame and hot gas through them some, tending to make ignition slower and compensate for the charge weight difference.

Hatcher has an extreme example of that in Hatcher's Notebook. He had two similar burning rate powders, one with a short grain and the other a long grain. The arsenal loading machinery could meter the short grain to an extreme spread of 0.6 grains, but could only meter the coarse grain to an extreme spread of 1.7 grains (huge error by a handloader's standards). Yet ammunition loaded on that machinery using the coarse grain powder proved consistently more accurate than the short grain loads did, and became that year's National Match load and several records were set firing it.

Hatcher credited that performance to the ignition characteristics of the longer grain powder, and I think stick powders in general ignite more reliably than sphericals. One year I ran Accurate 2520 in my M1A, but could never get groups to tighten up as well as I could stick powders until I started deburring the flash holes. Then they snugged right up. None of the stick powders I used showed any change when I deburred flash holes for them, so this would seem to verify their ease of ignition and lack of pickiness.

This is also a reminder to try to work up loads that aren't to sensitive to powder charge. I once had a .308 load using Sierra 155 grain MatchKings and Brigadier 3032 powder that was even more insenstive than Hatcher/s example. It ran from around 41 to 43.5 grains, IIRC without the groups changing size. On the other hand, I had a 4895 load in that gun under the 168 grain MatchKing that drilled little tight clusters, but if you changed it eve a quarter grain, they opened up. I'll take the wide range load any day of the week. Don't have to worry about how your powder measure did or worry about it changing temperature or anything. Just load it and shoot it.

As to stick powder in the progressive, rather than invest in an electronic solution, I'd recommend the JDS Quick Measure. They make an adapter for progressive presses. The measure design can't cut powder grains, so it tends to drop stick powders very consistently. Within 0.2 grains in my experience. I've seen one online test review where the tester didn't do as well with it, but he still declared it measurably better than the Redding 3-BR, which is nothing to sneeze at.

Stabilizing the bench may not solve all your issues, but anything that improves consistency can't hurt.
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Old June 26, 2011, 05:04 PM   #6
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During load work up it can be easy to indentfy a range in which small charge differences really don't affect accuracy very much, if any, at normal ranges.

Even with cases as small as .22-250 I've found that a spread about .5 gr. of IMR 4064 mean nothing on target. By adjusting my power measure to the middle of the good range I can simply drop charges without weighting every charge to .1 gr. or better. Larger cases have wider windows for good results.
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Old June 26, 2011, 06:50 PM   #7
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All good points.
I had actually thought of vibrating the powder drop to try to compact the charges more consistently (like a concrete vibrator ), then decided it may be easier/better to try to avoid vibration, rather than create it...

That might be a question I should direct to Hodgdon...

I do find, much of the time, that .5 grains can make a huge difference. Goinf from 43 to 43.5 grains in the 7.62 x 54R load I was working up, opened up my group from 3" to 5" at 225 yards.
Maybe insignificant for hunting, but definitely a difference when punching paper or steel at longer range.
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