• If you are being asked to change your password, and unsure how to do it, follow these instructions. Click here

Case fill and burn %

coop2564

Well-Known Member
Joined
Jan 6, 2015
Messages
1,264
Location
Texas
What do you consider optimum for case fill% and burn%? What do you consider the low side limits?
 
90% plus on fill. Burn rate to match bullet+cartridge parameters. Book will guide powders.

COAL is also a big deal unless you go by book.

QuickLoad has the tools to indicate %fill and %burn. GRT might as well but I am being slow to learn it over QL for 10 years plus.

I have other tools as well but those are attainable easy enough.
 
What about your burnt rate % based on barrel length, powder burn rate? You always strive for 100% or in some cases is 90% burnt good?
 
What about your burnt rate % based on barrel length, powder burn rate? You always strive for 100% or in some cases is 90% burnt good?
QL calculates all that.

I prefer %100 but it's not absolute. It's what is accurate.

My personal is that too low a %burn makes it harder to be accurate. "Upsets" the bullet on barrel exit. Lots of slomo video on YouTube shows it. Will the bullet stabilize after "distance"? I think so.

Perfect is not perfect. Preference is confidence.
 
90% plus on fill. Burn rate to match bullet+cartridge parameters. Book will guide powders.

COAL is also a big deal unless you go by book.

QuickLoad has the tools to indicate %fill and %burn. GRT might as well but I am being slow to learn it over QL for 10 years plus.

I have other tools as well but those are attainable easy enough.
I recently got GRT but its really off on many of my calibers, like 6.5 Grendel its way off on pressure and velocity for me using TAC and CFE223. My Hornaday book shows max at 31.2 cfe223 using 123 eldm @2500. GRT with all that data plugged in show that is 17k under max and only 2200 on velocity. Some others it shows to be off on fill and burnt % too, compared to my reloader books. so having a hard time thinking its worth spending any time on.
 
What about your burnt rate % based on barrel length, powder burn rate? You always strive for 100% or in some cases is 90% burnt good?
Per my previous response, I prefer >90%, so most strive towards a 100% fill ratio and sometimes beyond.

1734670077943.jpeg

1734670104008.jpeg
 
I recently got GRT but its really off on many of my calibers, like 6.5 Grendel its way off on pressure and velocity for me using TAC and CFE223. My Hornaday book shows max at 31.2 cfe223 using 123 eldm @2500. GRT with all that data plugged in show that is 17k under max and only 2200 on velocity. Some others it shows to be off on fill and burnt % too, compared to my reloader books. so having a hard time thinking its worth spending any time on.
GRT is free, isn't it?

An extremely quick and dirty on QuickLoad comes up with that exact FPS on a 6.5 Grendel+123 ELDM and indicates "max".
QL shows same FPS with 28.9 of TAC.

QuickLoad may be a valid investment for you.

Is this 6.5 Grendel one of your rifles? If yes, gas or bolt? Barrel? COAL you intend to use? I can "refine" and find full case full burn.
 
BTW: It seems hard to reach %100 burn with the 6.5 Grendel in my quick and dirty model.

High 90s fill, easy.

So far the only powder that makes %100 fill, %100 burn is Accurate 2495 at 29.1gn.
 
Yes, its free and mostly based on Europe data and powders. If I plug in like 30-06 using reloader powder its real close. But off using many Hodgdon powders, some are close within 100fps and maybe 2k on pressure. But my 6.5 grendel is 18" gas. If you have any data for 85gr hammer hunter or 123gr eld on TAC. my 85gr is 2.1660col, the 123 2.245. case is 35.8 h2o.
 
the slower the powder and shorter the barrel= less burn/burn completion. for the slowest powders you need a longer barrel and/or smaller case capacity. slowest powders tend to perform better in longer barrels as velocity won't decrease as much as medium to medium slow does (again it depends on case capacity). take something that holds 80-100grs with 8133, rl50, h50, 24v41 and 20n29 and with a 30" barrel you still might not get 95% burn rate. i like at least 92% fill and have gone as much as 115%.
 

Recent Posts

Top