Powder drop tube

[country gent]

I'm working on a new drop tube and stand. Stand is 14" tall and has a "shelf" on the top. Base is 5 1/2" wide and 8" long Shelf is 5 1/2" wide and 13" long. wood is poplar as that's what I had handy. I have a piece of 3/8" of X .250 ID X 36" long brass tubing ordered from online metals. Also a piece of 1/4" thick X 6" wide X 12" long aluminum plate that's going to be a leveling plate.
My idea is to set the scales ( RCBS Dial o Grain) on the shelf in front of the tube. Drop charge from measure into scales and trickle up if needed. from there a short trip up to the funnel on the drop tube to charge the case. The Belding an Mull measure I use will be on the shelf of the bench along side the stand.
Ive got the stand about done. ( I'm leveling the pad and shelf with clear epoxy now for a dead level surface to work from). Then Drill and fit the 3/8" hole for the tube. I'm polishing the tube off and on and about done there. I have a funnel made that's a little shallower and bigger than the rcbs are. The rails for the tube are 1 1/2" thick on top a 1" space then a 3/4" rail for a 3 1/4 spacing on the tube. I have to decide on the bottom case funnel. A stop for the tube. and a padded finger grip area for lifting it. I'm thinking a 3/8" brass washer soldered to the tube for the stop, or a 3/8" stop collar ( this would be adjustable also). For the case funnel I haven't truly decided much yet. Ill get the pad and shelf leveled with the clear epoxy and a couple coats of oil on it. Then worry about the case funnel.

[rfd]

i used a 30" aluminium arrow shaft and funnel, the allen keyed collet set the tub height, and a "washer" cut out of mouse pad foam to keep the granules from bouncing out of the case during the drop ...

https://i.imgur.com/0rnoPIt.jpg

https://i.imgur.com/Poiw80t.jpg

[country gent]

On my old drop tube the tube was 1/2" of aluminum X 3/8" Id. I had a 30 wsm case here I cut the head off of and used that for the end it sat into the case nicely and the shoulder sealed it. Since the smallest cartridge I plan on using in this is 38 caliber ant the largest is 45I may try the same thing here.

[calaloo]

My drop tube is a piece of 3/8 stainless tubing. I flared the bottom so that it sits atop the shell. The stand is made of oak and the bottom piece has a blind 1" hole. I turn brass bushings that sit in the hole with an appropriate center hole to accurately position the brass.

[Knarley]

My drop tubes are made out of that hard plastic (PVC?) plumbing pipe, about 28" taped to a piece of wooden moulding. A funnel is taped to the "top". The ID for one fits a 45-70 case, and the other fits a 38-55 case that will stay in the tube when inserted. No need for a stand.
Knarley

[DHDeal]

I load for both 45/70 and 40/65, and found the best stop for the tube are o rings. I drilled holes in the oak contraption my drop tube slides into and o rings allow me to move the tube up and down when necessary without loosening any set screws/thumb wheels. When they break or wear out, I put new ones on. They easily hold the copper 30" tube with attached funnel up for extended periods. A lifetime supply would probably set you back $1.39. You can probably buy a large amount of some high performance synthetic rubber o rings for $4.63 if you wanted to splurge.

Like someone else mentioned, I too add a good flair to the bottom of the tube and if it's below the mouth of the case about 1/8" no BP bounces out even with a case full.

I have a couple aluminum arrow shafts as back up, but the copper tubing won't ever wear out.

[country gent]

I thought about the o rings also. They do work. I'm still thinking on it. The stop collar isn't all that expensive and with a small thumb screw would be secure and quickly adjustable for different case lengths since I recently added 44-40 to my list. Ive also considered turning up a wood ring with a couple o rings in it for the stop. This could be made from a piece of the same poplar and finished the same to match the frame nicely. I'm still thinking on it.

[rfd]

the only really important item for a drop tube is the "powder washer" to keep the kernals from popping out of the case during the drop.

[Lead pot]

209752209753

A drop tube can be made very simple. I have a 10",20" and 32". I use 3/8" OC type K ridged and a 3/8" OD X 5/8" OD sweat adaptor that will fit over a .30-30 case to the .50-90 and it will not spill powder filling the case.
No stand is needed to hold the tube just put it over the case and drop the powder.

[country gent]

Well found some clear wood restorer made by JB weld. Its a 2 part epoxy mix clear and hard. I used it to "level" the shelf and pad where the cases will sit. Did a nice Job there leveled out nicely, cured in the stated 12-13 hours had a good working time, and very few air bubbles in it when cured. Grain of the wood shows thru nicely. Appears to be close to the finish Remington uses. I was going to do this with regular clear epoxy but have never been overly pleased with those results. This is for counter tops, Doors, and table tops and such where a very hard durable surface is desired. I have used Mirror coat in the past but it takes application of heat to get bubble out and is a odd mix ratio. This Poplar was pretty open grained so it soaked in good and should make a nice surface. Instructions claim up to 1/8" thick is good or more applications.

[country gent]

Tested the drop tube today. Used a 270 wsm case for the funnel neck down so it sets into the case and the shoulder centers it. Tube is 3/8" of and 1/4" id 36" long. a rcbs funnel fitted to the top for now. Since the scales sits in front of the tube, I made a lever mechanisim to raise and lower the tube also.

I set it up with the RCBS 505 scales on the shelf. Threw one charge of 68 grns 2 f olde ensforde powder. Got 2 45-90 primed cases and dropped thru the tube. Removed case and weighed it same weight did this 25 times with no bridging or loss of powder. ( till I dropped the case LOL).
Yesterday I glued the tube in the cut off 270 wsm case to fit it to the tube, its a snug fit and is removeable if desired. I also lightly polished out the tube with 320 grit sand paper on a 3/16 dowel. Straight line polish so lines flow in direction of the flow.
This drop tube seems to be pretty handy. A extra plus to the lever is a couple 3 quick taps makes sure all the powder is dropped. The lever gives enough travel to go from 44-40 case to 45-90 maybe 45-100 with out readjusting the stop. Used 2 stop collars one for solid stop one for lever to work on.
Its now useable and ready to go on the bench, I may polish the brass tube bright tomorrow though, just for grins and giggles.
The top of the shelf and pad were coated with a 1/8" thick coat of clear JB wood restorer for a hard durable surface. You can hardly file or sand it. The poplar I used for thishad been drying for several years since purchased and really sucked up the tru oil finish The handle area of the lever was also finished with 1/8" coat of the JB wood restorer for durability.