Go Back   CMP Forums > CMP General > Ask Each Other > Reloading
Register FAQ Members List Calendar Mark Forums Read

Reply
 
Thread Tools Display Modes
  #21  
Old 11-11-2019, 07:50 AM
britrifles britrifles is offline
 
Join Date: Aug 2014
Posts: 275
Default

I was hoping Varget would be the one powder that would work for my .30-06 (M1 and 03), .308/7.62 and .303 British loads. Varget shoots great in my .303 and 7.62 Lee Enfields but H4895 seems to do better in my M1 than Varget.

None of my wood gun rifles show any improved accuracy by weighing charges. My Redding measure dispenses both powders to about +/- 0.1 grain, occasionally 0.2 gr. it’s not worth my time to weigh every charge, so I’m a Reloader. I’d rather spend the time on the range where the most improvement in scores can be made by practice.
Reply With Quote
  #22  
Old 11-11-2019, 11:36 AM
WindLogik WindLogik is offline
 
Join Date: Dec 2012
Location: Washington State
Posts: 2,272
Default

Quote:
Originally Posted by britrifles View Post
it’s not worth my time to weigh every charge, so I’m a Reloader. I’d rather spend the time on the range where the most improvement in scores can be made by practice.
This handloader or reloader moniker is a bunch of snobby crap. The task is to load the best round for the application. Weighing charges and turning necks for shortline shooting with a typical vintage rifle (oddly something you see quite a lot) is stupid. You're making the right choices.

Universally at matches, whether it be sling or F class, I never hear the winners talking about their reloading technique. Reloading (handloading) is not complicated. It's manual labor that comes at the expense of components and time.
Reply With Quote
  #23  
Old 11-11-2019, 03:59 PM
Unclenick Unclenick is offline
 
Join Date: Nov 2010
Posts: 1,078
Default

Weighing vs. volumetric dispensing is something that gets argued from time to time. Either one may be the better choice under different circumstances, and there are reports of both weighed and volumetrically dispensed charges producing the smallest groups.

To understand how that is possible, you have to consider the basic reason for measuring charges is to dispense consistent amounts of chemical potential energy into each cartridge. Given the variations in weight you get from volumetric measures, it is easy to assume weighing will always do that best. Usually it does, but that is premised on stable powder storage conditions and uniform post-dispensing settling.

Powder can absorb up to 1.5% water weight over time, so, if you kept your powder in Arizona for a couple of years and then moved to Olympia, WA with it, after it had time to adjust to the higher humidity, you could find your weighed charges had to be increased by 1% or more to dispense the same energy content into each case. That represents more dispensed energy difference than a volumetric measure that ignores water weight would make, assuming you brought it from Arizona and used the same metering cavity setting. In that case, the volumetric charge would represent dispensing potential energy most consistently.

But simple energy content is not the dominant problem in that example. As its water content goes up, a powder's burn rate goes down. The Norma manual shows powder kept in a desiccated (near 0% RH) atmosphere has nearly 12% higher burn rate than the same powder kept in 80% RH, so the actual energy content of the powder would have to be increased in Seattle as well, meaning neither dispensing method for the Arizona charge could escape adjustment.

By the way, that last paragraph describes one of the several reasons load manual data from different sources often disagrees, even when measured peak pressures match. If the powder storage RH conditions weren't the same, neither will the results be, not even if they have the same lot of powder.

One point of digression here: Assuming you don't use sealant on both ends, Norma shows that water can move in or out of a cartridge past the surfaces where the case meets the bullets and primers. It is slow, but if you move a non-sealed cartridge to different RH storage conditions, after about a year the powder has gained or lost enough moisture to match powder stored in those same conditions prior to load assembly. This is a major reason you never want to store cartridges with a desiccant, especially not maximum loads. It could raise the powder burn rate enough to raise pressure and throw load performance off any sweet spot you may have hoped it would stay on.

Given stable storage conditions, some stick powders in some cartridge and bullet combinations seem to self-compensate for volumetrically dispensed charge weight errors. This is because an overweight charge that came out of the same metering cavity setting is one that was more densely packed in it. More dense packing means slower flame front propagation between grains which means slower effective burn rate. If it slows just the right amount, it compensates for the fact more total potential energy was in the slightly heavier charge.

An example is in Hatcher's Notebook in which he describes two similar burn rate powders he tested for National Match ammunition one year (this was in the 1920s or '30s, IIRC). One was a short-grain powder the Frankford Arsenal volumetric charging equipment could meter within 0.30 grains. The other was a long-grain powder the Arsenal equipment could only meter to 0.85 grains precision. Yet, in every test he did, the ammunition loaded with the coarse grain powder and all that variation produced consistently smaller 600-yard groups. It was adopted for that year's NM ammunition and several records were set using it.

As always, reality is clear as mud and exceptions have to be allowed for. What can you do?

Store your powder in about 60% RH. That's a compromise between Normas and Hodgdon's numbers and will work with both. Keep it constant by setting up a storage box with a Golden Rod heater and a humidistat (cheap didgital ones may be had on eBay). Remember that even a carefully screwed-on lid or a seamless plastic bottle has a finite water vapor transmission rate and eventually the powder will equalize to the storage conditions, even in one of those. Then load your ammo in similar conditions and store it in similar conditions if you aren't going to shoot it soon.
__________________
--------------
Nick

Gunsite Orange Hat Family Member
CMP Certified GSM Master Instructor
NRA Certified Instructor
NRA Patron Member
ORPA Life Member
Reply With Quote
  #24  
Old 11-12-2019, 02:07 PM
WindLogik WindLogik is offline
 
Join Date: Dec 2012
Location: Washington State
Posts: 2,272
Default

Quote:
Originally Posted by Unclenick View Post
Weighing vs. volumetric dispensing is something that gets argued from time to time. Either one may be the better choice under different circumstances, and there are reports of both weighed and volumetrically dispensed charges producing the smallest groups.

To understand how that is possible, you have to consider the basic reason for measuring charges is to dispense consistent amounts of chemical potential energy into each cartridge. Given the variations in weight you get from volumetric measures, it is easy to assume weighing will always do that best. Usually it does, but that is premised on stable powder storage conditions and uniform post-dispensing settling.

Powder can absorb up to 1.5% water weight over time, so, if you kept your powder in Arizona for a couple of years and then moved to Olympia, WA with it, after it had time to adjust to the higher humidity, you could find your weighed charges had to be increased by 1% or more to dispense the same energy content into each case. That represents more dispensed energy difference than a volumetric measure that ignores water weight would make, assuming you brought it from Arizona and used the same metering cavity setting. In that case, the volumetric charge would represent dispensing potential energy most consistently.

But simple energy content is not the dominant problem in that example. As its water content goes up, a powder's burn rate goes down. The Norma manual shows powder kept in a desiccated (near 0% RH) atmosphere has nearly 12% higher burn rate than the same powder kept in 80% RH, so the actual energy content of the powder would have to be increased in Seattle as well, meaning neither dispensing method for the Arizona charge could escape adjustment.

By the way, that last paragraph describes one of the several reasons load manual data from different sources often disagrees, even when measured peak pressures match. If the powder storage RH conditions weren't the same, neither will the results be, not even if they have the same lot of powder.

One point of digression here: Assuming you don't use sealant on both ends, Norma shows that water can move in or out of a cartridge past the surfaces where the case meets the bullets and primers. It is slow, but if you move a non-sealed cartridge to different RH storage conditions, after about a year the powder has gained or lost enough moisture to match powder stored in those same conditions prior to load assembly. This is a major reason you never want to store cartridges with a desiccant, especially not maximum loads. It could raise the powder burn rate enough to raise pressure and throw load performance off any sweet spot you may have hoped it would stay on.

Given stable storage conditions, some stick powders in some cartridge and bullet combinations seem to self-compensate for volumetrically dispensed charge weight errors. This is because an overweight charge that came out of the same metering cavity setting is one that was more densely packed in it. More dense packing means slower flame front propagation between grains which means slower effective burn rate. If it slows just the right amount, it compensates for the fact more total potential energy was in the slightly heavier charge.

An example is in Hatcher's Notebook in which he describes two similar burn rate powders he tested for National Match ammunition one year (this was in the 1920s or '30s, IIRC). One was a short-grain powder the Frankford Arsenal volumetric charging equipment could meter within 0.30 grains. The other was a long-grain powder the Arsenal equipment could only meter to 0.85 grains precision. Yet, in every test he did, the ammunition loaded with the coarse grain powder and all that variation produced consistently smaller 600-yard groups. It was adopted for that year's NM ammunition and several records were set using it.

As always, reality is clear as mud and exceptions have to be allowed for. What can you do?

Store your powder in about 60% RH. That's a compromise between Normas and Hodgdon's numbers and will work with both. Keep it constant by setting up a storage box with a Golden Rod heater and a humidistat (cheap didgital ones may be had on eBay). Remember that even a carefully screwed-on lid or a seamless plastic bottle has a finite water vapor transmission rate and eventually the powder will equalize to the storage conditions, even in one of those. Then load your ammo in similar conditions and store it in similar conditions if you aren't going to shoot it soon.
I've heard this before. Volume vs. mass. Some of this makes sense. But, hobby/consumer volumetric powder measurement gadgets really aren't that great, and they certainly arent that great for stick powder. A simple test is this: If I chrono very carefully made rounds from both my Redding measure and my Autotrickler lab scale, I get way, way better velocity statistics from the weighed charges.

Shortrange benchrest guys will throw charges to save time and for ease. This is meaningful to me. I have shot rapids and prone at 300 and seen no perceptible difference between weighed and thrown charges. Distance has a lot to do with how the round should be reloaded.

Regarding temp sensitivity, the Montana state director did and interesting test during one of their big matches. At these matches, LR 800 900 1000, everyone is shooting Varget (good temp performance). He provided a monetary award to everyone that was in the X ring for their first sighter at each stage. Very few were given. He did this to provide data to fish and game regarding the long range hunting trend. The arguement is that most folks would not be able to make a long range shot on an elk with their 10,000 dollar rifle because they are likely not practiced and also the unfavorable physics that are involved.

Envrionemental conditions and quality of the rifle have A LOT to do with the cold-bore first-shot accuracy at longer distances, probably more than the powder that is used. I think it is a mistake that one keyword factor, temperature sensitivity, is responsible for accuracy on the first shot or two. If the round is not at max and the powder is not too fast for the cartridge, I don't think it matters all that much.

Last edited by WindLogik; 11-12-2019 at 02:09 PM.
Reply With Quote
  #25  
Old 11-12-2019, 03:01 PM
Gewehr43 Gewehr43 is offline
 
Join Date: Nov 2009
Location: Denver, CO
Posts: 2,613
Default

Since I've chimed in on this, I'll chime in again...…..

"......Envrionemental conditions and quality of the rifle have A LOT to do with the cold-bore first-shot accuracy at longer distances, probably more than the powder that is used. I think it is a mistake that one keyword factor, temperature sensitivity, is responsible for accuracy on the first shot or two. If the round is not at max and the powder is not too fast for the cartridge, I don't think it matters all that much...……"



Noone that I've read (and certainly not me) is saying the question of powder selection (and it's temp sensitivity) means much at short range. So this discussion is about LR- 800-1000+ yds. That idea is reinforced since we are talking about a powder that is named "Staball 6.5." So we are talking about a powder being marketed to LR shooters.

I've never said that powder selection is the sole factor in your first shot/s being fired and where they go. Now powder selection and consistent charges are the main factor in maintaining a low and consistent ES, that IS critical in good LR shooting.
But that is but one factor in shooting accurately at distance. As you point out, range and wind miscalculations can play a significant part in this as well.
But I can't control those, powder selection and charges, I can. I can minimize and maybe even eliminant that variable. So I can then focus on trying to master the other variables...…. it would be stupid to approach the challenge of LR shooting some other way.
__________________
Service Rifle.... RIP .... 1884-2015

Last edited by Gewehr43; 11-12-2019 at 03:29 PM.
Reply With Quote
  #26  
Old 11-12-2019, 03:52 PM
WindLogik WindLogik is offline
 
Join Date: Dec 2012
Location: Washington State
Posts: 2,272
Default

Quote:
Originally Posted by Gewehr43 View Post

I've never said that powder selection is the sole factor in your first shot/s being fired and where they go. Now powder selection and consistent charges are the main factor in maintaining a low and consistent ES, that IS critical in good LR shooting.
My response was not targeting you whatsoever. We can all agree that statistics and weighed charges are important for long range shooting. My first response was to Britrifles who is indeed shooting at shorter ranges. AND, he can call himself a handloader or a reloader or precision cartridge craftsman or whatever he pleases. Those insisting on this "handloading" moniker have spent too much time with their hands.

Great, a "temp stable" ball powder. I will continue to weigh my long range loads on a precision lab scale, and for this reason I have no reason to use a ball powder. I can stick with my proven, "temp stable" stick powders. I'd be surprised if the longrange shooting communities, NRA (F-class and sling shooters that shoot patterns on bullseye targets ) or precision rifle, adopted a ball powder.

Last edited by WindLogik; 11-12-2019 at 03:56 PM.
Reply With Quote
  #27  
Old 11-12-2019, 04:42 PM
Gewehr43 Gewehr43 is offline
 
Join Date: Nov 2009
Location: Denver, CO
Posts: 2,613
Default

Sir:
No issues at all. I was simply being careful to explain that my opinions were just that, mine and my approach to this.

Yes, time will tell if this (the powder) lives up to it's hype...………. in this limited test, it did not.

https://www.youtube.com/watch?v=lcy8zqclIns

I shoot H4350 and see no reason, yet, to change but ……….
__________________
Service Rifle.... RIP .... 1884-2015
Reply With Quote
  #28  
Old 11-17-2019, 08:51 PM
.22shooter .22shooter is offline
 
Join Date: Mar 2010
Location: VA
Posts: 2,221
Default

Some of y'all clearly have extra time in your hands judging by the length of your forum posts.

ONE guy said he is going to try it out of all that hot air I just scrolled past. I hope we hear from him

Bill

Sent from my SM-J700T using Tapatalk
Reply With Quote
  #29  
Old 11-17-2019, 09:47 PM
Unclenick Unclenick is offline
 
Join Date: Nov 2010
Posts: 1,078
Default

WindLogik,

My assumption is you keep your powder stored under relatively consistent conditions. That's the key to making weighing superior to most volumetric dispensing. I think I laid out the conditions (mainly humidity shift) under which volumetric dispensing becomes more consistent in controlling the energy dispensed.

It's not clear to me that commercial volumetric dispensing is more precise than home volumetric measuring equipment. I just haven't seen it except once, in the Winchester example below. In addition to Hatcher's experience, I've pulled and weighed charges from LC M2 Ball that were loaded with WC852 (H380 in cannister grade) and found about a 0.8-grain spread in the charges. I don't own a measure that can throw that uniform spherical grain powder that inconsistently. By comparison, some Winchester Supreme .308 Match I pulled years ago that was loaded with 748 or its twin, showed a pretty astonishing 0.05 grain spread over the 20 rounds in the box on my lab scale, but my Redding BR-30 throws it very close to that. I've pulled Federal GM308M and found a 0.4-grain spread in the 4064 charge it uses. That's about as good as I've found in commercial ammo for a long stick powder, but my JDS Quick Measure beats it, on average, by about 0.1 grains.

It would be interesting to learn, since the samples I pulled were all done awhile ago, if the situation has changed. Perhaps pulling a box of commercial 6.5 CM intended for long-range would be informative. I don't know.

I gather some of the newer electronic dispensers have picked up speed, but something I've done in the past with the Quick Measure is to tare my scale with a primed case, then dispense the charge and check the weight and keep only the ones that hit the weight within 0.05 grains. That way I had both weight and volumetric dispensing done simultaneously. This was 308 W in Lapua brass weight-sorted to be as sure as I could that it all came off the same tooling. It seemed to go almost as quickly as the old PACT electronic dispenser I have, and the scale I used drifts less. The results were SD's in the 6-8 fps range, though I found it can be sabotaged if I don't take care to seat the primers optimally (0.003" reconsolidation with a K&M Primer Gauge Tool).

I haven't proved it to myself yet, but David Tubb claims hBN coating causes his first shots to go in with the rest. That'll be a check-it-out project for next year.
__________________
--------------
Nick

Gunsite Orange Hat Family Member
CMP Certified GSM Master Instructor
NRA Certified Instructor
NRA Patron Member
ORPA Life Member
Reply With Quote
  #30  
Old 11-18-2019, 01:09 AM
WindLogik WindLogik is offline
 
Join Date: Dec 2012
Location: Washington State
Posts: 2,272
Default

Quote:
Originally Posted by Unclenick View Post
WindLogik,

My assumption is you keep your powder stored under relatively consistent conditions. That's the key to making weighing superior to most volumetric dispensing. I think I laid out the conditions (mainly humidity shift) under which volumetric dispensing becomes more consistent in controlling the energy dispensed.
Maybe so. I can say that of the competitive shooters and reloading geeks I've talked with that are focusing on longer distances, not a one uses "volumetric" dispensing, and, almost universally, stick powder is used. Given the shot-to-shot statistics you can get with modern auto dispensing lab scales, I'm convinced that weight-measuring does lead to a consistent charge. With very carefully prepared brass and weighed charges, I have been able to achieve 8 shot statistics with an extreme spread of ~8 FPS for Palma loads.

My powder is stored the same, and I generally load out of the same lot, so weight measurement does provide a consistent charge. If there were some kind of moisture diffusion, as you mention, seems to me that would affect my whole box of rounds? Personally, I don't think it's constructive to worry about that kind of thing.

Last edited by WindLogik; 11-18-2019 at 01:33 AM.
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 07:07 AM.