Case fill and burn %

Huntaddict said:

I don't live in a vacuum. I hunt and shoot in reality

I have done this for years and have no issues with my set up and my system.

Single digit SDs. Great Accuracy. Great results.

Didn't really need coaching. was more sharing my experience.

Click to expand...

memtb said:

Sir, we all made mistakes in life…….some of us even admit those mistakes and learn from them! Thankfully most of us choose not to repeat our mistakes by altering our procedures!

I've made many, thankfully I was blessed with the opportunity to correct them! In those rare occasions…..you may not get a second chance!

Continue on as you see fit! memtb

Click to expand...

memtb said:

I see this mentioned quite regularly, and each and every time……I am left bewildered!


This is for a hunting rifle…….not intended for a hunting rifle. This will take two seasons…….summer then winter! Patience is a virtue !


Develop your load in the hottest ambient temperatures you're likely to ever encounter when hunting. Allow the rifle and test ammo to reach ambient……though not in direct sunlight. Work up to your maximum that gives the accuracy that you desire.


Then, once winter is set in, allow the rifle and ammo to once again reach ambient temperatures. Now shoot across your chrono to verify your velocity and it's accuracy. If the accuracy is acceptable……you simply adjust the scope for the velocity difference if any!

I'm pretty darn certain that this will alleviate high temperature, high pressure surprises!

Perhaps I'm just a simpleton……but this seems a very logical approach to preventing the high pressure situation that we see mentioned on this and other forums many times! memtb

Click to expand...

Mike D Texas said:

I do my best to strive for 100% (+) case fill and 100% burn inside the barrel.

Click to expand...

ARlife4me said:

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%.

Click to expand...

Michael Lares said:

Have played around with cartridges trying to get 100% fill when I have 100% burn. Started seating bullet deeper which of course changed starting psi and also time in the barrel. If a person has good brass and even better turns necks, bullet jump up to .250" on my bigger gun did not effect accuracy (.338 / .378 Weatherby). A guy in Montana set me on to that years ago. He was running .408 / bigger stuff. I believe this also was easier on the gun / throat.
I always try to get 100% burn % fill. Powder choices have huge effect.

Click to expand...

Brathany said:

I used to think this method was acceptable, but then found that the loads I made up and shot good in the Summer didn't do good in Winter & vice versa. Precision wise.

So, I have winter & summer loads reaching the same velocities using different charge weights. Sometimes even different powders.

Click to expand...

memtb said:

Exactly……hence my reason for saying they must be tested for precision and velocity at expected hunting temperatures! memtb

Click to expand...

ARlife4me said:

getting the most efficiency sometimes doesn't mean 100% burn or best accuracy (wish it did). what i've noticed using ql is the lower the muzzle pressure the more efficient it is. the 408 and bigger stuff makes sense on a 1/4 jump when bullets are 2.5" long or longer.

Click to expand...