loading by volume...

[LongRange]

darkker i started to post this in another tread but figured id start a thread instead of cluttering up the OPs thread.

im honestly NOT trying to be a smart A$$ or calling you out and i knew the title would catch your eye.

i have a few questions as ive been wanting to test your/the load by volume method for some time now...but i do have my doubts and need to put those doubts to rest...the reason i have doubts is because of the results I GET by weighing and trickling...

http://i1239.photobucket.com/albums/ff515/LTT-/Mobile%20Uploads/1454853623.jpg (http://s1239.photobucket.com/user/LTT-/media/Mobile%20Uploads/1454853623.jpg.html)

and also because ive questioned a few of the guys i shoot next to in F-class that also shoot bench rest and they all WEIGH their charges...this is one of the guys i shoot next to...i know this is an old record and may have been broken by now but if i remember correctly he holds about 9 records and did pretty well at the berger nationals with a shot out dasher barrel...

http://www.hornady.com/in-the-news/latest-news/hoppe-sets-record-105gr-amax-bullets

my questions are...
what do YOU use to load by volume?
how many charges do YOU weigh to get your average?
is the number 0.07916667 always the same?
you say powder will absorb moisture so how often should i double check volume to weight?
any more info i need to know or you want to share before i test this?

the biggest reason i want to test the "load by volume" is because i can see it being a big time saver if it pans out....id do it today but i have other things i need to get done and also would like to hear what you have to say first...next saturday we have a practice match so if its decent sunday i will get to this then.

[darkker]

my questions are...

1) what do YOU use to load by volume?
2) how many charges do YOU weigh to get your average?
3) is the number 0.07916667 always the same?
4) you say powder will absorb moisture so how often should i double check volume to weight?
5) any more info i need to know or you want to share before i test this?
.

1 - I use CC's, specifically I use a Lee PPM, or Lee dippers. I was going to use powder measure once, but that unit didn't have volume units, just hashes.
2 - Honestly, only 3 for an 8 # Jug. I haven't bought a 1# in a long time.
3 - No. That number always moves. Unless it worked out that that many CC's weighed that much, in your testing. The number is how many grains/unit of volume, in my example that unit is CC's.
4 - Good question, and this is the tricky one. How do you store your powder? There is a great article in the newest Norma manual, testing/discussing how much moisture change affects burning rate; even from a SEALED container! So how long you store powder, how much the temp and humidity varies, all plays to it. Most don't know that the S.E. corner of Washington is a desert, 3" total precipitation last year! I personally test mine every 4 months. I'm not sure what is "Right", but it works for me.
5 - There is some very good info in Modern Reloading on this, if you want to know more about volume. But here are some suggestions for you.

-Remember this is for extruded powder only.
-How ever you decide to do your volume test, do it Consistently. If when weighing, if 0.1gr is important; then carry that particularity over to the volume side.
- Don't confuse the two methods. Don't try and take your favorite weight load, and make it directly translate to volume; they are different.
- All things depend. So as an interesting aside to this. MZ5 and I go back and forth on this rather frequently. When we have gotten together and used the Pressure Trace to test loads, we have seen some interesting things. If you follow when I post the pressure traces, sometimes you can see that the trace is a bit wild, sometimes it's consistent. We have done both volume and weight for those traces.
MZ5 thinks I'm an idiot, and I'm convinced that he is; as it relates to the PPM. So who is correct? I can get consistent results with his,he cannot. So it would appear that neither of us is wrong, just a difference of methodology. Two such lots of one powder were VERY consistent in burn rate. The next powder was quite different.

Please do post your results, whether or not you find results that cause you to change your system; I am glad you are trying it!

[yobuck]

Im interested in this topic. Its been many years since ive visited a varmit class benchrest match.
But at least back then quite a few of the shooters were just dropping the powder directly from the
powder measure to the case. They all did have good powder measures however many of which were
upgraded Lyman 55s at that time. No doubt better ones are available today. Even a grain difference in powder
charge as a rule dosent move the bullet much when testing loads.
I personaly dont think record groups prove much as to just the load. Same as a pitcher throwing a no hitter, all things
just came together that particular day.

[LongRange]

1 - I use CC's, specifically I use a Lee PPM, or Lee dippers. I was going to use powder measure once, but that unit didn't have volume units, just hashes.

I HAVE BOTH THE PPM AND THE DIPPERS...I WILL TRY BOTH AND SEE WHERE I END UP..

2 - Honestly, only 3 for an 8 # Jug. I haven't bought a 1# in a long time.

ALL 8LB JUGS HERE AS WELL

3 - No. That number always moves. Unless it worked out that that many CC's weighed that much, in your testing. The number is how many grains/unit of volume, in my example that unit is CC's.

I WILL USE CCs AS WELL....SO IN MY CASE 45.8G X 0.07916667=3.62583349 CCs SO ILL ROUND THIS OFF TO 3.70CCs OR AM I WAY OFF HERE?

4 - Good question, and this is the tricky one. How do you store your powder? There is a great article in the newest Norma manual, testing/discussing how much moisture change affects burning rate; even from a SEALED container! So how long you store powder, how much the temp and humidity varies, all plays to it. Most don't know that the S.E. corner of Washington is a desert, 3" total precipitation last year! I personally test mine every 4 months. I'm not sure what is "Right", but it works for me.

I STORE MY POWDER IN MY SAFE...I HAVE AN 4LB BAG OF KINDRY IN MY SAFE AND LIVE IN NORTHERN NEVADA SO ITS DRY HERE...

http://i1239.photobucket.com/albums/ff515/LTT-/Mobile%20Uploads/1456076814.jpg (http://s1239.photobucket.com/user/LTT-/media/Mobile%20Uploads/1456076814.jpg.html)


5 - There is some very good info in Modern Reloading on this, if you want to know more about volume. But here are some suggestions for you.

I HAVE THIS BOOK AND WILL TAKE A LOOK...

-Remember this is for extruded powder only.

THIS IS ALL I USE...

-How ever you decide to do your volume test, do it Consistently. If when weighing, if 0.1gr is important; then carry that particularity over to the volume side.
- Don't confuse the two methods. Don't try and take your favorite weight load, and make it directly translate to volume; they are different.

GOTCHA...


Please do post your results, whether or not you find results that cause you to change your system; I am glad you are trying it!

im in caps above and i will post when i get to this...this will be perfect because i have some peterson brass i want to play with as well...i turned the necks this morning and will finish the rest of the case prep later today.

[LongRange]

Im interested in this topic. Its been many years since ive visited a varmit class benchrest match.
But at least back then quite a few of the shooters were just dropping the powder directly from the
powder measure to the case. They all did have good powder measures however many of which were
upgraded Lyman 55s at that time. No doubt better ones are available today. Even a grain difference in powder
charge as a rule dosent move the bullet much when testing loads.
I personaly dont think record groups prove much as to just the load. Same as a pitcher throwing a no hitter, all things
just came together that particular day.

if this proves to be accurate i will buy a harrells powder measure...and i agree about record groups...theres more to them than just the load...but when they talk i tend to listen.

[darkker]

I think you missed a point. the number 0.07916667 is NOT something you should use, that was from an example only!!
You have to do the VMD for yourself.
As far as rounding-off. I would say, that it depends on how exact you want to make the comparison. If you would normally weigh to 0.1 of a grain, then you don't round to the nearest grain, so don't round the decimal that short when doing volume.

When doing my VMD's with my measure, I choose something close. Again, this is only an example; and the tie to weight is only a reference, not a direct tie.
For my 308 or Creedmoor, I take the VMD around 3.8cc; because that give a weight that is relatively close to what I would charge with. If the 308 case takes 35-45gr of any powder, which would ROUGHLY translate to the 3.8cc range. Don't do a VMD calc at 1.0 cc. While my PPM is *Supposed* to be calibrated in actual CC's, I don't expect a perfect calibration; it is only a $10 tool after all.

[schnyd112]

Darkker-

do you load at or above published max when you use this method? I could see loading a rifle that gets shot 100 times per outing, mid to high pressure, but not sure if i trust it near or above max. My reasoning is this:

1. rounding up can get hairy in a hurry. Let's use LR's example, of ideal volume of 3.62 being rounded up to 3.7. This is only an example, I have not actually figured any of this out.

Let's say 40 gr of powder x will yield 3.62 cc of volume. That gives us slightly more than a grain of powder to .1 cc. Rounding then from 3.62-3.7 would give almost an entire grain more of powder weight. If you are on the edge of showing pressure signs at 40 grains, and you round up to 3.7 cc, you will be very close to now 41 gr of powder, probably now getting a sticky bolt, if not blowing primers.

2. I will have to read your other thread, but volume is just a tricky devil to measure consistently, every time, when using an odd shaped solid. Like Archimedes, irregular solids can have volume measured by watching how much liquid they displace when submerged. I know you don't want submerge your powder but how do you check to make sure your measurements are the same powder density each time? Eg when I drop 4 grains of powder, depending on how the grains fall, it fills the pan on my scale differently. One cockeyed grain gets stacked with another and then there is air between them. How do you account for this? (I know what I am asking, just not sure if it makes sense types out)

3. Again, I will have to read your other thread but the margin of error seems bigger when using a larger unit with less significant figures. 37.5 grains is pretty good, 37.50 is better, 3.8 cc's just seems to have a larger variance before you notice a change.

4. If powder absorbs moisture, is that not going to change the density, weight, and volume of the powder? Not linearly, but any change in weight seems like it would also affect the volume.

I am not questioning your method, I am just asking questions about it. I will read up and see if I can grasp what is going on in your other thread. I reload for my pistols "roughly" powder measure to case and I check weight about every 25 throws. I reload my rifle at the top accuracy node I can, sometimes that can be a grain or more over published max and usually close to seeing pressure signs. Hell with my swift I had to back way off then I started shooting competitions in 90+ temps. After 10 rounds I was smearing case heads pretty bad. But it liked to be shot fast. The hotter I loaded it, the better it got.

i know guys that use a powder measurer to load for precision, but they throw a charge a little light, then trickle up on the scale to get exact. My scale will move with the addition of 1 kernel of powder.

[darkker]

I use the method for everything. Other than a VMD, I haven't weighed powder in a few years. That said I also rarely get to book max velocity, Things never group as well there are you wish they did. As it turns out, most of my accuracy loads are mid-range on speed. If you are using data from a manual, for the grains, and think those are set in stone.... Oye Vey!!! They aren't there to copy, they are there for a reference.
Let's address your concerns.

1) First is Pressure signs, no one can see Pressure signs(Without the equiptment), they see the results from, only. Your chronograph shows signs. When you can match/approach book max, you in fact are at or already ABOVE max Pressure. So, if you don't round up to the nearest whole grain charge normally, don't round up your VMD, just like I stated earlier.

2) You have fallen for the trap. NOT density, VOLUME!! Density is a weight, we don't care about weight, only volume. That is why I said, the VMD is your number, from your method, in your powder. It is a reference, not a standard to be copied, no different than load data.

3) The margin of error.... In terms of its weight, but we don't care about that. We care about its volume. As I've said a few times, don't round to a small cute decimal. Burning rate is controlled by geometry, and inversely tired to the BD.

4) Yes, which if loading by weight, causes a false weight that is aggravated in a changed burning rate. When loading a volume, the grains could be solid lead, or feather light; how many sticks fill an area will not change with its density. The moisture issue will also affect a volume system, just not to the extent that weight will.
Accurate scales have been around since Roman times, yes? Not the same with volume devices. Weight is safe and easy so most data gets printed that way today; it wasn't always that way.
Human nature is to do things simply and assume many things.
Back to your "Pressure signs" comment.
The fact that you went over book max grains doesn't tell us anything. Velocity does. Until someone can say what alloy and heat treat spec their cases are, no one can tell me they can read signs of Pressure, until they are WAY over. I've posted this several times, but here she is again.
This had no "signs" of ANYTHING. Cases and primers looked great, kick ejection, etc was great. Simply starting in the middle of the data, and not using the chrono from start; would have had us believe nothing was wrong.
http://i78.photobucket.com/albums/j84/Darkker13/Mobile%20Uploads/Screenshot_2015-01-31-15-00-18_zpsmopqcu83.png

Those are called secondary Pressure spikes, that is how you blow guns apart. Ask Charlie Sisk, of Sisk Rifles.

[FW Conch]

darkker, since the velocities in the above example were not out of line, can we assume it was the structure of the Deep Curl pills that caused the pressure spikes? Or something else?

I don't intend for this question to lead us off "LR's" OP. :-)

Thanks...Jim

[m12lrs]

if this proves to be accurate i will buy a harrells powder measure...and i agree about record groups...theres more to them than just the load...but when they talk i tend to listen.

Well I can tell you what my experience is telling me.

Start with the chargemaster. My experience is they have an accuracy of about 15 hundreds of a grain or worse. I have one. I was working on trying to get my SD's down. Now it reads to a tenth so if it says 24.2 you believe it right. Some reading a little research and I got curious.

Bought a gempro scale accurate to 0.02 grains. Found out what I thought I was getting and what I was getting were nowhere close.

So I started weighing and trickling. Waiting on the chargemaster to drop a charge got old so I started throwing charges with a lee perfect powder measure. Took it another step and added the omega electronic trickler. Now I was fast and accurate. Noticed with the right powders, ball powders, that I could set up the powder measure where it might throw 3-5 charges in a row that all I had to do was weigh and dump.

anyway weighing and trickling brought my ES and SD's down where I wanted them ES around 10 SD's around 4. Now there was a lot of other reloading tricks along the way.

So now I am coming around full circle. When do you need this accuracy and when is enough enough. You can often find an accuracy node that is 0.3 grains wide. That means any powder charge in that range should have the same POI. That is within reason.

So I have a Harrell precision BR powder measure (just for your information it is no more accurate than the lee perfect powder measure but it sure is pretty and those bearings make it slick handling) and for most of my reloading I set the charge with the scale and then just drop charges. For my long range stuff I weigh and trickle.

[earl39]

Darrker i noticed you keep referring to extruded powders. Should i take it ball powders are different? I weigh my charges then set my powder thrower to throw that weight charge which equates to X (volume) = y (target weight). Unless you are measuring the volume of each case and filling to a percentage i don't see how one way is better than the other except for speed in loading. I have witnessed vertical at long range due to inconsistent charge weights. Would this mean inconsistent volume? I don't know the answer to that but using the lee dippers on extruded powders i (and i am speaking only for myself here) have never been able to get consistent charge weights. I can't believe two charges thrown back to back should weigh different amounts. Maybe an hour apart or day or week ( your humidity factor) but not back to back. This is why i ask if it is something mainly concerning extruded powder.

[LongRange]

ok so i did a little playing around yesterday with the PPM and my scale while waiting for some brass to finish tumbling.
now i know that loading by weight and volume are two different things and when loading by volume that im not so much concerned with weight...BUT...i know for a fact that by doing little things differently i can vary the charge weight with a PPM by 1.5g so i was looking for the most consistent way to throw charges with the PPM and the only way i have to reference that difference is by weight...again i know weight is irrelevant when loading by volume i was checking for the best way to get consistent drops.

the powder was H4831sc...my target weight is 45.8g...the VMD 0.0725 was the number i think(i dont have all my numbers in front of me)which was 3.3205cc if i remember correctly...so i set the PPM to 3.3205 according to the instructions and threw 20 charges...as i said i dont have my numbers in front of me but this was the worst of the 4 tests i did with a weight spread of 1.4g...2nd 20 i tapped the hopper two times each throw with the handle up to settle the powder into the chamber and it wasnt much better 1.2g spread.
third 20 i tapped the handle two times each throw while the handle was up and this was quite a bit better .7g spread.
the last 10 i tapped the chamber area two time each throw with the handle down and this seemed to be the best method with a .4g spread.

now some of the spreads above may be because the PPM i used is still pretty new so its not fully broken in and part of it may be some static still in the unit(and yes all parts where wiped with a dry sheet)so i will most likely use my PPM ive had for 8yrs as when its set to a weight it drops 90% within .3g and an occasional .5g spread.

again i know im not so concerned with weight BUT i still like to know whats going on.

all of this testing will be done with H4831sc in fully prep'd peterson brass(similar to lapua and nosler in external and internal weight capacities and neck thickness)BR2 primers in a 28" shilen select match 260rem on a long action savage and 142g SMKs...this barrel shot bug holes when i pulled it to play with that 260AI with 45.8g of H4831sc BR2s and a 142g SMK at .025 off the lands...i will put this barrel back on this week and shoot an OCW by weight to verify the load and fire form the brass and then load 10 by weight and 10 by volume and shoot them side by side...5 each at 100yds and 5 each out farther if the first 10 group well.

[darkker]

1-DarKKer i noticed you keep referring to extruded powders. Should i take it ball powders are different?
2-I weigh my charges then set my powder thrower to throw that weight charge which equates to X (volume) = y (target weight).
3-Unless you are measuring the volume of each case and filling to a percentage i don't see how one way is better than the other except for speed in loading. I have witnessed vertical at long range due to inconsistent charge weights.
4-Would this mean inconsistent volume?
5- but using the lee dippers on extruded powders i (and i am speaking only for myself here) have never been able to get consistent charge weights.
6-I can't believe two charges thrown back to back should weigh different amounts.

1 - Yes, Very different!! So this premise works on Extruded for a couple of reasons. 1 is that they have their burning rate controlled by Geometry(size, shape). 2 is because of the inverse tie and closely held BD to BR correlation. Ball powder on the other hand has it's burning rate controlled by coatings. So if the BD goes up(more power) the burning rate doesn't have a corresponding slowing mechanism. With volume you CAN get yourself into trouble pressure wise with volume, much much faster when using volume.
2 - That is using a volume measurer to dispense a weight, not the same thing. If that makes you happy, that's great; but it isn't loading by volume. Back to to moving BD of powder.
3 - In part due to a shifted burning rate, because of a shifted BD.
4 - Yes
5 - You don't want consistent charge weights, you want a consistent volume.
6 - This is due to a fluctuating BD, be it from Nitro, or H2o.



1 -now i know that loading by weight and volume are two different things and when loading by volume that im not so much concerned with weight...BUT...i know for a fact that by doing little things differently i can vary the charge weight with a PPM by 1.5g so i was looking for the most consistent way to throw charges with the PPM and the only way i have to reference that difference is by weight...again i know weight is irrelevant when loading by volume i was checking for the best way to get consistent drops.

2 - the powder was H4831sc...my target weight is 45.8g...the VMD 0.0725 was the number i think(i dont have all my numbers in front of me)which was 3.3205cc if i remember correctly...so i set the PPM to 3.3205 according to the instructions and threw 20 charges...as i said i dont have my numbers in front of me but this was the worst of the 4 tests i did with a weight spread of 1.4g...
3- third 20 i tapped the handle two times each throw while the handle was up and this was quite a bit better .7g spread.
the last 10 i tapped the chamber area two time each throw with the handle down and this seemed to be the best method with a .4g spread.

4 - now some of the spreads above may be because the PPM i used is still pretty new so its not fully broken in and part of it may be some static still in the unit(and yes all parts where wiped with a dry sheet)so i will most likely use my PPM ive had for 8yrs as when its set to a weight it drops 90% within .3g and an occasional .5g spread.

5 -again i know im not so concerned with weight BUT i still like to know whats going on.


I'm glad you are giving this a "go" LR. In the end you may not choose to continue this method, which is fine. But I believe that you will find merit in it.

1 - This is the part you need to let go of. The connection to weight is only a reference, Nothing more. You are correct that the Lee can vary, I assume that all measures can, but I have only used the Lee; so this is about it. There are several methods of "breaking it in" that I have read. The one I personally used was to buy a tube of very fine powdered graphite, open the thing up, ALL parts, and get a Q-tip and completely get everything covered in the thought of not having a "sticky, or static-y" surface for the powder to hang on to. Again, however you choose to meter, ALWAYS ALWAYS do it the same way. Personally I like a 2-tap on filling, and a 2-tap on empty. But ALWAYS do it the same. The weight will always vary, but it doesn't mater because we don't want a weight anyhow.
2 - I have heard that some powders are large enough that they don't play well, don't know if this is one of them or not; however. Do whatever you do the exact same, every time. You are trying to fill a volume and then dispense it, not meet a weight goal. Also remember that book data is supposed to be a reference for loading and not a standard to be copied. You may find that your 48.5gr weighted charge which works well, isn't the same as when you are using that weight to approximate into volume.
3 - Remember that you are not looking for a weight. So the spread isn't the concern, the consistency is.
4 - I kind of got off track, this is covered in #1.
5 - You do know what's going on, you just need to understand that you do. :) Don't know if you bake or not, but it may help you to visualize. Buy a bag of coarse ground, whole wheat flour and dump a large amount in a bowl. Grab a measuring cup, 1 cup sized. Scoop it full, scrape it off flat. THAT volume is 1-cup, not a weight; no cookie recipie calls for any weight of flour, they call for a volume of flour. If you were to weigh that cup of flour, and repeat it, the weight will ALWAYS vary, because of particle size. That is really no different than what you are doing with the gunpowder. No one gets excited that they don't know how many pounds of flour are in their cookies, don't get excited that you don't KNOW how many grains are in the case.

Again the larger picture to concern yourself with is being consistent with your meter. It is the same mindset as being particular in your charge weights. If when you load by weight, you load to an accuracy of 0.1gr. Then you also want your measure to throw as close to the same VOLUME as it can, each and every time.

A practical example of how I do my loads, and I don't claim I'm right with this; it's just what works for me.

***EXAMPLE ONLY***
If the book I'm using shows a Start - Max range of say, 38.1gr - 46.2gr. Use your VMD and convert that to a CC range, lets say that makes it 3.677cc - 3.922cc. So as with all good loading technique, you start low, at 3.677cc and see where your velocity compared to the book is, this will give an approximate correlation of YOUR lot of powder, compared to what was tested for the book data. Now you can begin your work-up to an accurate load. Again you should always test your velocity while going up, to ensure you don't get on the wrong side of pressures.

Some powders like the VERY progressive stuff from General Dynamics and one from Rhinemetal don't have a regular burning curve, and the curve changes with pressure. So watching velocities all along the way will keep you safe. If suddenly velocities don't increase as you would anticipate, you need to back down. An interesting example of that is with a ball powder we tested, Superformance. Due to the curve shift with pressures, the difference between 50,000psi - 60,000psi is only approx 50fps. So at least in my Creedmoor, I run in the 50,000 psi range. Keeps barrel heat down, keeps wear down, gives-up essentially nothing in velocity.

[LongRange]

Gotcha....

ive read up a little on volume and I think I have a pretty good grasp on it now so when I start I will start .5g above book min and work up and chrony the loads as I go...I put my shilen barrel back on my long action tonight so I will at least fire from the Peterson brass and get some load and velocity data Sunday.

[darkker]

Very cool. Please share your results!

[scooterf79]

Very cool. Please share your results!
What he said, I'm really interested in this. I think I understand it...especially with the baking analogy.....Im the sweets maker here at the house so that worked great lol.
Scooter

[LongRange]

What he said, I'm really interested in this. I think I understand it...especially with the baking analogy.....Im the sweets maker here at the house so that worked great lol.
Scooter

a picture in your bakers apron or it didnt happen!!

[cm12setx]

You all have me thinking on this subject, to Google I went and found these two links.
http://www.tacticoolproducts.com/powder.pdf
http://www.leeprecision.com/cgi-data/instruct/VMD'S.pdf

it list powder and cc to gn .
wanted to share with you all.
And really like this thread because I am learning more about reloading.
Thanks

[LongRange]

Thanks for the links cm12 and stay tuned there's more to come.

[LongRange]

so ive got some volume numbers worked up...i was going to shoot an OCW by weight but then thought why this is about volume so im going to do this entire test by volume including the OCW...i ran the numbers for the OCW just like i would normally do by weight but took the numbers and converted them to CCs.

my question now is theres a LOT of numbers when converted to CCs like 3.06675cc or 3.34225...with the PPM i know that i set it on 3 and then go 3 more turns then to 4 on the thimble but what about the 225?