I think I disagree with a couple points, but not in a contentious way, more like an exchange of ideas.
Turk favors the ball powders because they meter well. I don't disagree with that opinion at all, but I asked a very well-recognized powder supplier to recommend a powder that would meter well and allow me to drive a 175SMK at 2700fps and offer consistent accuracy capable of .5MOA groups with an M1A, if all else was up to the task. His reply was
I would recommend either IMR4895 or CMR100. You will find that the single based propellants ('stick') are much more stable and consistent than the double based (ball) types.
I won't mention his name because I don't want to start an argument, but several Expert shooters recommended him as a knowledgeable source with regard to reloading, so I followed his advice without experimenting with ball loads for the M1A. (I never followed up, so I don't know what he meant by "more stable and consistent".) I know that’s not much of a reason to favor extruded powder, but I decided to follow his advice on the faith in his experience and expertise.
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The electronic ones do a much better jb, but are too slow to keep up with a progressive.
As usual, I agree with Steve as he's expressed this opinion, but I rigged an electronic measuring system that I almost cannot keep up with on a semi-progressive Dillon 450 (and as I understand it, a 550 is semi-progressive also). I've never seen a Dillon 650 in action, but my impression is that it is fully ‘automatic’--that is to say, one can crank the handle without any other physical actions required, and each crank produces a finished bullet. If that's the case, I would guess that time spent waiting for the electronic dispenser with my system when using a Dillon 650 would be about 4-6 seconds (maximum) per cycle. I've timed my reloading (for 100 rounds) when using a semi-progressive like a 450; a round made with a 'press-dropped' powder charge is about 1-2 seconds faster than a 'hand-measured' powder drop (it took less than 2 minutes more for 100 hand-measured loads). The minimal lost time is because the time used “waiting†for the dispenser to finish is used to insert a new bullet and rotate the shellplate. By the time those two physical actions are done, the newly dispensed charge is usually already waiting.)
I'm sorry this is so long-winded and the following, so detailed, but once it's set up, it's proven to be a speedy and accurate system for me.
I have the PACT 110V electronic dispenser and scale. I set them up according to directions, but the dispenser is mounted 1/2" above the tabletop (shimmed with a couple blank CD cases that are taped to the tabletop). I replaced the OEM plastic scale pan with a toy pot (2" tall, about 2 1/2" diameter, from Walmart's kitchen section). Behind the scale I bolted a powder measure stand and installed a threaded drop tube so I can screw in a Lyman55 (and switch Lymans for different loads; used Lymans are extremely accurate and fairly cheap, costing ~$40on EBay). I made the powder measure stand out of an L-brace, a piece of metal pipe that I had threaded, and 2 water hose clamps, which are used to hold the pipe to the L-brace. I attached a tiny hand-made funnel to the end of the drop tube (my threaded pipe). The funnel has a 90 degree bend at the end of it; the funnel forces the powder to drop out of the measure, curve, and then dispense into the pot horizontally (because when powder is dropped from any height vertically into any container, it bounces, like tiny BB's, and spews out everywhere). This horizontally-oriented nozzle at the end of the funnel allows me to touch the inside wall of the pot to the funnel and 'cushion' the drop so none of the powder is lost, as the powder swirls around in the pot like a whirlpool and settles. I drop a charge within .3gr of my desired load with the Lyman55, put the pot on the PACT scale, and press the actuator button on the PACT dispenser and it functions as a trickler, and takes about 3-4 seconds to finish up the load. (using this regimen, the only time I've lost is the time it takes to drop the powder into the pot, hit the actuator button on the dispenser, retrieve the pot later, and drop the charge into a funnel on the reloading press. It took longer to type this than do it.) 80% of the time the charge is dead on, and the rest of the time, I'm +- .15gr. I didn't know one could measure to .01 gr margin of error without a beam scale. Steve, did you mean .01, or do you measure each charge with a beam scale? I haven't seen a PACT nor RCBS electronic scale (reasonably priced) that can measure in hundredths.
Thanks for your patience, and I hope this helps.
