Copper spiral BP powder drop

[MOA]

Since I located a 1895 Ideal Black Powder measure so it was time to do a BP build for this dedicated BP measure. This is the project. It will progress bit by bit over the coming weeks as I have time to put it together. Today was the start. A word of caution is warranted here. If your using a torch, be sure to keep your fingers out of the flame. Ouch.

Here's the start of the new powder drop made with 1/4" ID copper tubing. I've decided to do a spiral tube using a 2" rolling pin as the form. This will give me a 34" tube drop in a 22" distance. I took a large sheet of paper and drew a line at a 45 degree angle that was 34" in length and then rolled it around the 2" rolling pin so I could follow the line around the form with the copper tube. The tube angle should stay at the 45 degree angle which should allow the powder to fall and compact at the bottom. The tube was crimped at one end and then filled with solder and then the tube was filled with water so it would not collapse when being wound around the form. The other end was crimped but not soldered, I didn't think enough water would leak out while winding the form to collapse the form, and I had the un-soldered end up at the top and not at the bottom,(which it didn't when I wrapped it.) The top was taped to keep that section straight and the bottom end was also kept straight to facilitate the pour. I now can measure how long the vertical support needs to be and put together the base support and all the tube clamps.















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[Drydock]

By spiraling the tube you will be reducing the velocity of the powder grains as they fall into the case, reducing the settling of the powder. Instead of the powder reaching it's terminal velocity, the powder would slide into the case with little more effect than pouring it directly in from the measure. You would get better results just using the 22" straight tube.

[MOA]

That is a possibility no doubt Drydock. I will know more tomorrow after I do some drops and column height testing. I have a 36" drop tube I made last year, so if I need to I will just make a support backer for the measure and use it in conjunction with my other drop tube.

[country gent]

I vaguely remember an article on these by a writer many years ago. ( he was using pyrex clear tubing). His wasn't for back powder but for the big stick powders of the time like Imr 4064, 4350,4831 ect. His theory was the slide down the helix of the tube would align the long grains stacking them into the case better and tighter than a straight tube would. With BP it will be interesting to see the results.
The bend looks good and the helix angle looks like it should work also. Will be interesting to see the results.

If memory serves his reason for the clear pyrex was to see any bridging that occurred in the drop.

[samari46]

I seem to remember some old time plumbers filling the tube with fine sand to keep the copper tubing from collapsing. My folks house was built in the 1920's and there were still a few soldered copper tubes in the plumbing system. Course over the years they had to be replaced with new copper tubing and the copper elbows and other fittings that are common today. Frank