Factory ammo - charge weight variations.
- Thread starter mccraggen
- Start date
mccraggen":3r8v31oh said:
Try and find a copy of "PRINCIPLES AND PRACTICE OF LOADING AMMUNITION by Earl Naramore, copyright 1954. He give a fairly detailed explanation on how charges are loading into the brass.
In a nutshell the cases are set below sliding pieces of metal with holes set to hold the proper amount of powder. The powder is literally shoveled onto the metal and a squeegee type affair removes the excess. The the lower piece of metal slides out of the way and the powder drops into the case. His narrative is much more precise and detailed. I went from memory so it may not be quite correct but that's how I remember it.
Whether or not they still use that system is something I cannot answer.
Paul B.
1100 Remington Man
Handloader
- May 1, 2007
- 1,151
- 295
PJGunner you just described loading shotgun shell's on a progressive press as it is loading by volume for both shot and powder.
Now here is the rub some lots of powder weight different as does lead shot depending on the batch and how much anamonity it has and it changes from lots.
Good news in shotgun little changes 99% of the times it does not matter and some times it will make your load illegal in a Skeet or Trap event.
Use a scale.
Now here is the rub some lots of powder weight different as does lead shot depending on the batch and how much anamonity it has and it changes from lots.
Good news in shotgun little changes 99% of the times it does not matter and some times it will make your load illegal in a Skeet or Trap event.
Use a scale.
A
Anonymous
Guest
As mentioned, factory ammo (at least mass produced ammo) is loaded by volumetric powder measures.
I bet there's far more variability than we'd ever believe possible.
I bet there's far more variability than we'd ever believe possible.
Rocketvapor
Beginner
- Mar 31, 2017
- 88
- 8
Weight vs volume is a heated topic.
The powder manufacturers produce the powder to a controlled volume.
Large ammo makers run process control and quality sampling programs to fine tune the process. When they offer various grades of the same round then I would suspect that the lower priced lines are a little less precise.
If you could reload with a very precise volume then you could match loads done on Monday to those done the following Saturday.
Some people just plain believe their favorite throwing device, and even check the repeatability with weight, Duh
The general rule of +/- 0.1 grain gets tossed around a lot. Checking every 10th charge by weight is common. Besides, what does it matter?
Most shooting is done at 100yds or less. Velocity variations at 100 yards will produce minuscule vertical dispersion. Barrel nodes are probably at least 0.1 grain wide. See. Doesn't matter.
Super Brenchrest shooters toss charges, works for them.
Long range shooters need a more precise method of throwing most charges than +/- 0.1 grain especially with little cartridges like the .223, not so much with the 300WM. Don't agree? Fine, my opinion.
Now, back to the original post. I've pulled down ammo to reload to different specs. I seldom find a 0.2 grain variation, even with cheap foreign steel cased ammo. What I do find is bullet weight variations of +/- 2% with the cheap steel cased stuff and less than +/- 1% with U.S. brass. Running a 1000 75 grain bullets across the scale I typically get 74.6 to 75.4 grains.
Another thing I find is variations in brass weight (and likely volume variations). The "I use this brand/headstamp" works somewhat but I find a pretty wide range in brass weight within the same brand/year.
Telling us what brand you used doesn't really help much. I would like to also know you're selecting nominal components.
COL length variations, maybe caused be shipping and handling show up in factory ammo.
I think the home reloader can refine their process by quantifying the error sources, trying to make each 'insignificant', and performing multiple checks. Running 10 today, 10 tomorrow compared to running a 100 in a batch gives you 10 or 100 that might be EQUAL in performance. It's Equal that matters to us.
The powder manufacturers produce the powder to a controlled volume.
Large ammo makers run process control and quality sampling programs to fine tune the process. When they offer various grades of the same round then I would suspect that the lower priced lines are a little less precise.
If you could reload with a very precise volume then you could match loads done on Monday to those done the following Saturday.
Some people just plain believe their favorite throwing device, and even check the repeatability with weight, Duh
The general rule of +/- 0.1 grain gets tossed around a lot. Checking every 10th charge by weight is common. Besides, what does it matter?
Most shooting is done at 100yds or less. Velocity variations at 100 yards will produce minuscule vertical dispersion. Barrel nodes are probably at least 0.1 grain wide. See. Doesn't matter.
Super Brenchrest shooters toss charges, works for them.
Long range shooters need a more precise method of throwing most charges than +/- 0.1 grain especially with little cartridges like the .223, not so much with the 300WM. Don't agree? Fine, my opinion.
Now, back to the original post. I've pulled down ammo to reload to different specs. I seldom find a 0.2 grain variation, even with cheap foreign steel cased ammo. What I do find is bullet weight variations of +/- 2% with the cheap steel cased stuff and less than +/- 1% with U.S. brass. Running a 1000 75 grain bullets across the scale I typically get 74.6 to 75.4 grains.
Another thing I find is variations in brass weight (and likely volume variations). The "I use this brand/headstamp" works somewhat but I find a pretty wide range in brass weight within the same brand/year.
Telling us what brand you used doesn't really help much. I would like to also know you're selecting nominal components.
COL length variations, maybe caused be shipping and handling show up in factory ammo.
I think the home reloader can refine their process by quantifying the error sources, trying to make each 'insignificant', and performing multiple checks. Running 10 today, 10 tomorrow compared to running a 100 in a batch gives you 10 or 100 that might be EQUAL in performance. It's Equal that matters to us.
truck driver
Ammo Smith
- Mar 11, 2013
- 7,198
- 728
I'm going to stray from the original post a little.
When I first started reloading it was shot shells and the reloading press had a volume charge bar that you could change the bushings in for different powder and shot charges and I had a beam scale to check the powder charges. So naturally when I moved up to rifle cartridges I got a volume powder dispenser to throw my selected powder. Got very frustrated with it since I still had to check every charge on the scale it threw and just plain stopped using it and it still hangs the stand where I mounted it collecting dust.
Now I do have Dillon reloading presses I use for pistol ammo and have found the powder measures to be very accurate and consistent when using flake or ball type powders these again throw by volume but I always check them with a scale before I start and around every 25 charges to make sure it is still the same. I have found you have to maintain a certain rhythm and force with the lever to be consistent since the volume powder chargers will change with how you operate the press. With automated machinery I would think this is controlled and very repeatable.
When I first started reloading it was shot shells and the reloading press had a volume charge bar that you could change the bushings in for different powder and shot charges and I had a beam scale to check the powder charges. So naturally when I moved up to rifle cartridges I got a volume powder dispenser to throw my selected powder. Got very frustrated with it since I still had to check every charge on the scale it threw and just plain stopped using it and it still hangs the stand where I mounted it collecting dust.
Now I do have Dillon reloading presses I use for pistol ammo and have found the powder measures to be very accurate and consistent when using flake or ball type powders these again throw by volume but I always check them with a scale before I start and around every 25 charges to make sure it is still the same. I have found you have to maintain a certain rhythm and force with the lever to be consistent since the volume powder chargers will change with how you operate the press. With automated machinery I would think this is controlled and very repeatable.
"What’s factory ammo?"
It is that stuff that someone gives you that you shoot up for the cases to reload.
"Has anyone measured some of the companies consistency in charge weight or do they just to hell with it and let it go? Wondering what sort of effect it has on accuracy?"
I don't know of any bench rest shooters that shoot factory ammo so that will give you an idea.
When loading a large batch of rifle ammo I will use my RCBS powder dumper set to drop really close but just under the weight I want and measure every charge and trickle in the amount needed to be exact.
Pistol ammo with flake and ball powder I usually drop into the cases and weigh every 10th round to check.
When loading just a box, 20 rounds, rifle ammo I use the old Lee Dippers that will dip close but under the weight I need and then trickle in the rest weighing every load.
It is that stuff that someone gives you that you shoot up for the cases to reload.
"Has anyone measured some of the companies consistency in charge weight or do they just to hell with it and let it go? Wondering what sort of effect it has on accuracy?"
I don't know of any bench rest shooters that shoot factory ammo so that will give you an idea.
When loading a large batch of rifle ammo I will use my RCBS powder dumper set to drop really close but just under the weight I want and measure every charge and trickle in the amount needed to be exact.
Pistol ammo with flake and ball powder I usually drop into the cases and weigh every 10th round to check.
When loading just a box, 20 rounds, rifle ammo I use the old Lee Dippers that will dip close but under the weight I need and then trickle in the rest weighing every load.
