Charging method for best accuracy?

[mikecr]

There are several threads going which are related,,
http://www.accurateshooter.com/forum/index.php/topic,821075.0.html
http://www.benchrest.com/forums/showthread.php?t=65453
http://www.benchrest.com/forums/showthread.php?t=65311
http://www.longrangehunting.com/forums/f28/same-volume-powder-different-weight-48149/
For the most part these come down to weighing, weighing accuracy, scales, volume, humidity, etc.

I have been happy weighing powder with my tuned CM1500, and charging with a long drop tube. I assumed that powder needed to be weighed, as there is no other way to 'measure' powder with any precision. Atleast, not that I'm aware of.. And these good discussions leave me to wonder:

Are most accurate powder charges produced by weight, standard volume, or granule count?

I'm looking for input beyond point-blank-BR, as I'm aware that short range records are taken without regard to any of this.
THANKS

 

[SilverEagle]

I'm a 1K competior, all I do is weigh my charges to +/- 0.00 grains on a standard RCBS scale, and can shoot in the mid to high 190's
as far as humidiy and tempture, I load all my ammo in batches of 50 to 100 at the same time as to min. and variances

 

[SilverEagle]

my bad, fat fingers typed to many zeros....
I ment +/-0.0 grains

 

[mikecr]

I'm lookin for what you know, rather than what you do.

Are most accurate powder charges produced by weight, standard volume, or granule count?

 

[markr]

my bad, fat fingers typed to many zeros....
I ment +/-0.0 grains

Zero is Zero...it doesn't matter how many decimal points you take it to.
Let me know which model scale that you use to achieve zero!
Mark

 

[msnations]

I'm lookin for what you know, rather than what you do.

Are most accurate powder charges produced by weight, standard volume, or granule count?

The trouble with measuring by volume is that each charge will vary depending on how efficiently the granules decide to pack each time you pull the handle. This can yield acceptable results for some (many) applications, but the best consistency is achieved by measuring by mass (a 'grain' is a unit of mass after all, not weight).

 

[mikecr]

That's one vote for weight (easily measurable)

 

[Gearheadpyro]

+1 for charge by weight. I use a RCBS Chargemaster combo, it measures to 0.0 grains and throws it automatically. It is right about 97% of the time, when it's not its only by a pinch and is very easy to correct (it's usually caused by me shaking the bench anyways).
The problem with measuring by volume is that the powder can stack different ways such as to include varying amounts of air. The more air you have in the charge, obviously, the less powder you have. Charging by weight eliminates that problem.

 

[mikecr]

It's agreed that producing charges with consistant weight is easy.
But the question remains

Given three charge types;
1. Same volume
2. Same weight
3. Same number of powder granules

Which would produce lowest ES?

 

[2506]

Every scale I have ever seen will only be accurate to with in 1/10 grain. If you want more perfection than that it is call being anal. As long as you are with in 1/10 grain you will not be able to tell the difference in the loads. There are a lot more things that will factor in to the accuracy than being exactly the same weight on powder.

 

[mikecr]

That's
2) What I dos(including mine)
2) Votes FOR weighing
1) The endeavor is anal
1) Against kernel count
1) Volume may or may not be equal weight

Keep em coming

Given three charge types, holding;
1. SAME volume
2. SAME weight
3. SAME number of powder kernels
Which would produce lowest ES?

 

[mikecr]

I can relate gunamonth.
Details mean a great deal to me because I don't do this to compete(to be 'good enough' to win). I do it for the learning. I hope to 'win' comfort in my understanding of things.

I weigh because that's all I can do with precision right now.
I have also been using a VIC-123 for validation.
But in contrast to this approach, there are discussions going with implications that volume is a constant and weight can vary w/resp to it.

If I had missed this perspective, I would have been content with my approach. Now I have a new nag inflaming my SIMS(Self Imposed Misery Syndrome).

I appreciate all discussion here. This is a great place for peer checks

 

[boltman13]

Benchrest shooters, using very expensive and well designed powder measurers, very consistent manipulation of said measurers, and ball or very small stick powder achieve remarkable accuracy. True they are shooting amazingly consistent bullets in rifles that are as close to perfect as can be achieved, and from a very stable platform, but if accuracy was only a function of the consistency of the powder charge then they would probably weigh each charge on the most sofisticated and accurate scale obtainable in persuit of the ultimate in accuracy. They don't. Now low standard deviation on a shot to shot basis begins to make a difference as range increases, that only makes sense. Counting each kernel of stick powder is tedious at best, but probably impossable as a practical matter, only more so for ball powders. Even then there are minute variatios in each kernel. Weighing each charge with the most accurate scale available will not change the fact that primers, bullets, cases and bore fowling are also not constant

 

[Steve Blair]

I vote that weight produces the lowest ES. I no longer use a mechanical powder measure, probably because I cannot use them well enough. I also do not like the idea of cutting or crushing grains.

My Chargemaster sits next to the Acculab VIC 123 and is set to .2 grains below target weight. After the RCBS finishes, I manually trickle to weight on the Acculab. It seems fairly quick to me, but that may be because I am anal.

 

[boltman13]

An interesting way to get accurate measurment by wt. I can't afford an Acculab, but could throw aslightly lighter charge with my Redding Powder Measure and trickle to a final weight on my digital scale. I may try that as I have some reservations on the accuracy of my Lyman DPS II for long range loads. If this meathod gives better accuracy and smaller ES it would be worth the extra time it takes.

 

[RDavies]

I think one of the most important bts has been missed.
That is how loose or compresed the charge is.
If we are running close to 100% charge density, a round in which the powder was tipped in a bit more slowly, or the powder pan was given a few taps on the funnel, the powder will sit lower and not be compressed. In the next load which was poured in quickly, the powder might sit a bit higher and be compresed.
With some powders, being compressed will give different velocities than if it is packed a bit more loosely.
In my limited experience I think that H4350 has been slightly less sensitive, while H4831SC has given lower velocities hen slightly compressed. (While Varget velocities climbed).
This has only been with a few different calibers, nothing scientific.
It is why I have started going back to slightly faster powders (H4350 or AR2209) and lower densities. (90-95% or so).

It seems point blank benchresters dont worry too much about ES, 300M shooters slightly more so, but 1000YD BR shooters live by it. As for match rifle shooters shooting out to 1200-1500 yds, I think they would be pretty anal about it to.
I dont have a super duper electronic scale, so I just try to stay in the middle of a node to keep me a bit safer.

 

[Laurie]

[cr500]
It seems point blank benchresters dont worry too much about ES, 300M shooters slightly more so, but 1000YD BR shooters live by it. As for match rifle shooters shooting out to 1200-1500 yds, I think they would be pretty anal about it to.

large ES often doesn't make much if any difference at 100 yards, so it doesn't necessarily matter if the measure throws the odd charge that's 0.2 or 0.3gn out - although I bet your average BR shooter would love to get a measure that invariably throws its charges within a 0.1gn spread! (Incidentally, British 100yd BR competitors are increasingly pre-loading their ammo weighing charges rather than doing it on the firing point with a measure alone. We don't have continental US temperature and humidity changes here, so varying charges for the conditions is rarely an issue.)

Going back to the original point, I had a good example of it testing some .308W combinations off the bench at 100yd a couple of days ago. I'd knocked a charged case partly over when placing it in the press to seat a bullet the evening before. I knew I'd lost some powder - didn't think it was more than a few kernels - and carried on just making a mental note about that charge weight. On testing, it was cartridge number 2 in the string, and MV plummeted from the 2,640-2,661 range that the other four gave to 2,559 fps, some 90 fps down, so more powder lost than I'd thought! Where did the bullet go? Virtually through the same hole as the previous shot at 2,640 fps. If I'd stopped there it would have been a 0.1" or smaller group!

Since I'm loading for 500 -1,000 yards for BR and F-Class, I'd love to get charge variations down to nil. I've yet to see a measure including the two Harrells and electronic Lyman DPS that I've got that don't have regular fits, and I've virtually given up on the Lyman as it's so swensitive to tiny air movements and prone to drift. So, it's good old RCBS 10-10 beam scales that I love until I find something that's better (and which I can afford too).

Recent features on the AccurateShooter blog re electronic scales match things I've encountered and seen with others. An increasing number of shooters here are developing loads on the firing point using pocket battery operated models and I've seen results that are so far out weight-wise that at best they're useless, at worst bordering on dangerous. Many of these devices seem to be unreliable in the home environment, badly so in a barely protected shed!

The basic question - does it matter for the long-range precision shooter? Maybe, maybe not. But, like many, I'd rather I'd no variations at all in charge weights. Even if it gains one little in ammunition performance, it adds to the psychological side of shooter performance knowing the equipment is as near perfect as can be obtained.

Laurie,
York, England