Drop tubing

[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