Does a compressed load change the Burn Rate on Quickload?

[fatelvis]

Just wondering when upping the powder charge, and the powder begins to become compressed, does the burn rate factor (BA) change? If so, is there a method to predict the correct BA or pressure? Thanks Guys-

 

[Murray Brook]

No the BA factor does not change. Not sure how you could adjust for this.

 

[243winxb]

"Another important characteristic is its morphology. Shape and size have a profound effect on the burning rate and power generation of a
powder."
See post # 11 here.

Forensic Science Communications April 2002 — Volume 4 — Number 2

To many types and coatings on *powder, to lump then all together.

 

[D-4297]

Laurie did a testing of "Compressed Loads" and his findings appeared in the British Magazine for shooting . Can't remember the name of it offhand , but his findings were that there was no discernable changes in a compressed load , to a standard 95-99% load .

 

[Doom]

Reloading Bench | Target Shooter Magazine

 

[SeabeeKen]

I dont ever recall reading about any issues with extruded powders being compressed. I do recall other says compressing ball powders wasn't good. My personal experience with compressing ball powder has been when pulling bullets, i found the powder packed tightly together and requirings a straitghtened paperclicp to work it loose. Perhaps the nitroglycerin in it caused this. I did see pressure spike in some compressed h-414 some years back that should have been well within safe charge limits.
Only testing will reveal the answer

 

[fatelvis]

Reloading Bench | Target Shooter Magazine

Wow! Thank you for that link. I wasn’t aware that series of articles was even in existence. Lots of valuable information written by that gentleman.

 

[243winxb]

From link.

“Excessive powder compression can lead to potential problems with proper propellant ignition. Sometimes this can cause dangerous conditions. Never use excessively compressed powder charges.”

 

[D-4297]

From link.

“Excessive powder compression can lead to potential problems with proper propellant ignition. Sometimes this can cause dangerous conditions. Never use excessively compressed powder charges.”

Good comment . I think the "key words" are "excessively compressed" . I read pretty much everything Laurie puts out , because he gives documented data in his articles , and not just "opinions" .

 

[mikecr]

Load density definitely affects MV.
You can test it.
Load at about ~90% fill, point barrel straight down, ease up to level rest, and fire across a chrono.
Now opposite, point barrel straight up and ease down to level rest. Chrono reading is higher.
You can see this depending on how you charge cases as well. Like with a long drop tube & swirling pour.

I don't think anything accounts for this. I load to around 104% fill with QL (long drop tube), which is not compressed with any of my powders (yet).