Drop tubing

[Knarley]

Is there an advantage to drop tubing before compressing, or is it just an extra procedure?

Thanks,

KB

[fc60]

Greetings,

I use the drop tube when loading 40-65 Black Powder. The compression die only moves the column down about 1/16".

Cheers,

Dave

[BLAHUT]

Helps to settle the powder before compressing. I use one on all my big cartages with black or subsutute powders.

[Don McDowell]

You have to get the powder in the case whether you use a drop tube or a funnel so it’s not necessarily an extra step
Using the compression die to seat the over powder wad just assures an even seating depth

[Nobade]

Without the drop tube I can't fit all the powder in the case for my paper patch loads.

[dtknowles]

Like Nobade, I can't get the whole charge in the case without a drop tube. Drop tubes are like magic. I can't put 120 gr. BP in my 450 BPE cases with just a funnel, they overflow. Using the drop tube it all goes in and leaves more than a quarter inch of space in the top of the case to put in the wad and start the bullet. Then I don't need to use a compression die, I can just seat the bullet as the required compression force is small.
Tim

[Bent Ramrod]

You can check and see for yourself. Drop tube a charge into an empty case and dump the same charge into another case through the funnel without the tube. Pick up each case and tilt them slowly towards horizontal over a dish to catch the powder when it spills out.

I notice that I always get a few degrees more "tilt" with the drop-tubed charge before the powder starts to pour out than I do with the funnel filled case. This, to me, indicates that the powder grains are more closely packed together in the drop-tubed charge.

Of course, "drop-tubing" also implies a steady pour of the powder into the tube funnel over the course of several seconds, rather than just dumping it in and letting it find its own way into there. I give it 5 seconds or so; a count of eight.

We had a world-class Combustion expert at one of my jobs, who maintained that with loose powder, you could get a wide range of burn rates ("anything you want" was her phrase) depending on how "loose" the material was. Filling as much of the air space between the particles with other particles (by vibration or some other method) and compressing to a given value would give those same materials a remarkable consistency in their burn rates.

At another job, we had to blend lots of black powder to a given burn rate in safety fuse. The powder mixture was introduced into a lead tube, with vibration, then the tube was pinched off and run through a series of rollers that reduced the diameter and compressed the powder inside. A foot of this stretched and swaged lead tube was cut and it was put into a water cooled trough and burned at a constant temperature, and the barometric pressure noted. When the normalizing calculations were made on the time it took vs pressure and temperature, the measurements were remarkably close together, as long as the blend was homogeneous, and another calculation would transfer the lead tube burn rate to the burn rate expected in the safety fuse. Again, it was very close and very reproducible.

So, I drop tube and compress. It isn't just the lack of smoke and the higher pressures and velocities that made smokeless powder a technological leap; it was the reduction in finagling necessary to get an accurate load.

[indian joe]

Is there an advantage to drop tubing before compressing, or is it just an extra procedure?

Thanks,

KB

Drop tubing seems to get the powder charge more evenly packed in the base end of the case than you get with just compression

I reckon evenly is a word that rhymes with accurate

[HWooldridge]

I tried using light vibration a couple of times, but I was filling 44-40 cases to the brim and would always lose some powder. Worked better on 45-70 cases with 60-65 grs. Using a drop tube does help if you pour at a measured pace rather than a quick dump.

[FrankJD]

Drop tubing black powder into a case allows the powder granules to better compact for increased case capacity prior to compressing the powder.

[Gobeyond]

How long is a good drop tube? Is it necessary for 45 colt bp load? I can understand it in theory but my experience with 43 Mauser was undeterminant.

[steveu]

I have dropped tube and vibrated case and the level is the same before compressing. I prefer to vibrate the cases to speed things up, usually 30-50 at a time.

[dtknowles]

I have dropped tube and vibrated case and the level is the same before compressing. I prefer to vibrate the cases to speed things up, usually 30-50 at a time.

I think vibrating and drop tubing serve two different purposes. Drop tube to get a charge into a case that will not fit otherwise. Vibrating will settle a charge, but the charge must fit into the case with room to spare in the first place.

[dtknowles]

How long is a good drop tube? Is it necessary for 45 colt bp load? I can understand it in theory but my experience with 43 Mauser was undeterminant.

My drop tube is 30 inches long. I am not sure how much shorter it could be and still work but I am not cutting it shorter without strong evidence I am not ruining it.

Tim

[Don McDowell]

How long is a good drop tube? Is it necessary for 45 colt bp load? I can understand it in theory but my experience with 43 Mauser was undeterminant.

I use the Frankford Arsenal funnel kit with two extensions, and slow pour the charge. Works well on everything from 32wcf to 45 2 7/8.

[Lead pot]

I have drop tubes 6", 12", 18" and 30". I use the 12" the most.
The amount of powder you can get into the case depends on how fast you pour the powder from the pan into the funnel. I use the 12" the most because of the hight of my bench.
Using vibration makes dust from the particles rubbing together. just empty a vibrated case on paper and take a look. You can drop tube and then vibrate and you will see a higher level of powder in the case when you do this.
Using a drop tube that fits inside of the case mouth defeats the effect using a drop tube because when you pull the tube from the case you loosen the powder.
With the tube over the case neck the powder stays undisturbed.

You should pay attention to the post Bent Ramrod made. The consistent volume of the case holds does a lot more for accuracy than most other things. This is why I stress case prep a lot of times for getting accuracy.

313594

[GregLaROCHE]

I have a drop tube that’s one meter long, just because that’s the length they sold the tubing. I’ve tried the drop tube, simple compressing, as well as compressing after using a drop tube. For the same boolit, cards etc. I could never get any more powder in than compressing alone. Maybe tube dropping gives better powder burn, but not more powder in the same space, in my experience. I usually compress very hard.

[FrankJD]

Drop tubes compact the kernals of powder in order to maximize case capacity, compression is the next step. I drop fill .45-70 cases to the case mouth, then push in an LDPE wad, then use a press mounted compression plug to drop the wad .1" below the case mouth, or deeper if need be, depends on what a particular rifle likes. This is with Swiss 1-1/2F and that gives me an 82 grain load so that the load becomes a virtual .45-90.

[Castaway]

Think potato chips. Some settling occurs during shipping (drop tube). Sit on the bag and you’ve compressed them

[Brimstone]

Think potato chips. Some settling occurs during shipping (drop tube). Sit on the bag and you’ve compressed them

I did something to that effect with a bag of Cheetos as a kid. Orange dust and confetti as the opposite end popped open. On moms white floral pattern couch.

You really cannot appreciate orbital re-entry speed of mach 25 until a shoe enveloped in ionized plasma flies across the room at your head.

[Larry Gibson]

Pressure/testing, velocity testing and on target results (200 yards) with 70 gr (by weight) of GOEX Cartridge in the 45 70 compressed with a compression die prior to seating the 405 gr M1873 bullet revealed no measurable difference between a charge thrown into the case and one drop tubed into the case.

Perhaps the amount of compression may be a determining factor?

[dtknowles]

Pressure/testing, velocity testing and on target results (200 yards) with 70 gr (by weight) of GOEX Cartridge in the 45 70 compressed with a compression die prior to seating the 405 gr M1873 bullet revealed no measurable difference between a charge thrown into the case and one drop tubed into the case.

Perhaps the amount of compression may be a determining factor?

I believe the amount of compression has a non-linear effect on burn rate. Going from light to moderate compression causes an increase in burn rate but at some point, increased compression decreases burn rate. Velocity increases with compression when that compression is used to allow an increase in the powder charge.
Tim

[Huvius]

“increased compression decreases burn rate. Velocity increases with compression when that compression is used to allow an increase in the powder charge.”

I’ve often thought that an over compressed load could be detrimental to consistency.
Also, in my experience, a few light taps on the side of the case with a steel rod is the most consistent method of settling the powder whether drop tubed or poured in with a funnel.
Takes a little time but is very consistent for me.

[Rattlesnake Charlie]

When loading 4350 into .303 Brit it filled it to the very top of the case mouth. When dropped through a tube it nicely settled at the base of the neck. Just my experience.

[Abert Rim]

Very interesting experiment, Brimstone. In Latino culture, mothers are legendary for being able to hit errant children at distance with their "chanclas."
https://www.youtube.com/watch?v=7-Z2HAKTsjQ