Rifle case weight vs volume
- Thread starter BJung
- Start date
If you are a target shooter the above is totally irrelevant.
It two totally different aspects using similar tools.
I used to hunt and all I cared about was reasonable accuracy which was 1.5 inch MOA.
I target shoot now and you would not begin to pack my target guns out hunting.
I often have people oooh and ahhh over my groups (which I am not that impressed with most of the time). But they are hunters and I tell them my groups are irrelevant.
Hunting I never took a shot off hand, always braced, but it sure was not off a bench.
I hit in the area I was aiming at and that was what counted (oddly I never saw an animla with a target on its side).
So, what get you down to 1/2 MOA is not relevant in the hunting world. Might be a few hunting guns that can shoot that good (the family Sako 270 shoots 3/4 MOA x 5. So what. My 7mm shot 1.5 MOA and I got what I shot at as well.
Its not a right or wrong or better or worse. Hunting is an entirely different world than target shooting. The gun is only part of it. Stalking and logistics are more important than the gun. People hunted with WWI 1917 rifles. One guy I knew did not even know how to use the flip up sight or what it was for. He still got his deer. He was not a gun guy, he was a hunter. Gun was like a hoe to a farmer. Tool.
Shoot, hunting you might even save money though I never did. Cost me more when you add up the expenses. I liked it then and I respect it now. My neighbor is not a good shot, he gets his moose every year. That is what counts. I shoot his guns for him to make sure they are hitting where they should. Nope, he is not a gun guy.
Target shooting does not pay either (for most of us) but its our entertainment. So yes we get into the weeds because its our form of fun.
Maybe 8 years ago, I read an article by a guy who interviewed somethign like 10 of the top target shooters in the country.
When all was said and done, no two of them agreed on what worked. Yea they had some things in common, but one guy would swear by under 1/10 of a grain loads and the next would just dump it in.
Clean after every shot, no, clean after 10, no get it good and dirty and shoot etc.
Good case prep, reasonably powder, good bullets, a good gun setup all contribute.
But its the trigger puller that makes most of the difference.
Do the basics right and then work on the trigger pulling.
When all was said and done, no two of them agreed on what worked. Yea they had some things in common, but one guy would swear by under 1/10 of a grain loads and the next would just dump it in.
Clean after every shot, no, clean after 10, no get it good and dirty and shoot etc.
Good case prep, reasonably powder, good bullets, a good gun setup all contribute.
But its the trigger puller that makes most of the difference.
Do the basics right and then work on the trigger pulling.
you planning on using your mechanical beam to do case volumes? That should be entertaining
as far as reloading goes all I do these days is clean my cases, size them, chamfer the necks and load bullets. Loads are developed so I have less than 20 ES over a .3 grain spread. I do no annealing, no neck lubing, no bullet weighing, no case volumes, no primer weighing or any other nonsense.
Yet my match scores steadily improve and I keep setting new personal records in long range. Seems the more attention I pay to practicing and shooting the higher my scores get, go figure. I stopped being a reloader who liked to shoot and now I am a shooter who reloads
I think your question needs a purpose. Meaning what are you trying to accomplish or reduce . What specifically are the differences you are looking to find out ?
Accuracy
Velocity
Pressure
Safety at max charges and changing brass
IMO case volume is all you need but case weight can be helpful “if” the case weight differences from case to case are 8gr + .
I’ve done a lot of case weight and volume measurements and case volume has no correlation to what that case weight might be .
Since volume / space availible in the chamber and bore size from cartridge to cartridge greatly determines on how that cartridge is loaded and what powders are used . It would seem to indicate to me case volume or volume as a whole as a relates to internal ballistics is significantly more important than how much your case weighed . There is nothing I’ve ever read in any of my manuals that starts talking about what my cases weighed and how I should change my charge weights . They talk about different manufacturers and how they can differ but they don’t say simply weigh your cases , separate and load accordingly .
Can case weight help you understand if your case volume may be different than other cases ? Yes but its not Linial . The case weight has to vary quite a bit to guarantee a case volume difference . So if you’re separating your cases by a few tents or a half a gr here 3/4 of a grain there you are not going to see a consistent difference in any of the measurable‘s that matter in my humble opinion .
Accuracy
Velocity
Pressure
Safety at max charges and changing brass
IMO case volume is all you need but case weight can be helpful “if” the case weight differences from case to case are 8gr + .
I’ve done a lot of case weight and volume measurements and case volume has no correlation to what that case weight might be .
Since volume / space availible in the chamber and bore size from cartridge to cartridge greatly determines on how that cartridge is loaded and what powders are used . It would seem to indicate to me case volume or volume as a whole as a relates to internal ballistics is significantly more important than how much your case weighed . There is nothing I’ve ever read in any of my manuals that starts talking about what my cases weighed and how I should change my charge weights . They talk about different manufacturers and how they can differ but they don’t say simply weigh your cases , separate and load accordingly .
Can case weight help you understand if your case volume may be different than other cases ? Yes but its not Linial . The case weight has to vary quite a bit to guarantee a case volume difference . So if you’re separating your cases by a few tents or a half a gr here 3/4 of a grain there you are not going to see a consistent difference in any of the measurable‘s that matter in my humble opinion .
When we weigh our powder, what's an acceptable range +/- the goal? If you are weighing 56.0 gr of H4831, are you comfortable with a powder measure drop of 56.2 on occasion vs 55.9gr? Or are you dead-set on 56.0gr each time?
If so, stick the RP, Win and Fed cases because the average internal volume from the chart above between the 3 is 55.2gr and the deviation is RP -0.1gr, Win +0.2gr and Fed is -0.2gr.
Will that difference in air space above the charge make any difference?
If so, stick the RP, Win and Fed cases because the average internal volume from the chart above between the 3 is 55.2gr and the deviation is RP -0.1gr, Win +0.2gr and Fed is -0.2gr.
Will that difference in air space above the charge make any difference?
Bart B pretty well lays it out. And its not a direct relatioship betwen weight and volume (I did some power to powder testing and came up with about a 4/6 to 1.
As a case lays down, the space above it is not relevant. 80% fill or better is generally better but lots of exceptions.
Compressed may work better, but that is gun (or barrel by barrel/chamber ) you have to test.
My 7mm did not shoot any better with hand loads than it did factory. Go figure. Still shot more than good enough to hunt with (if I hit it it dropped down and I only had one miss, too long a shot and I still did a graze).
As a case lays down, the space above it is not relevant. 80% fill or better is generally better but lots of exceptions.
Compressed may work better, but that is gun (or barrel by barrel/chamber ) you have to test.
My 7mm did not shoot any better with hand loads than it did factory. Go figure. Still shot more than good enough to hunt with (if I hit it it dropped down and I only had one miss, too long a shot and I still did a graze).
For general practice/training mixed brass by caliber. For hunting loads or my precision type loads I separate by head stamp, and try to keep to to the same batch of brass if I can. Never sorted by weight or case capacity, that goes way beyond my my needs or abilities to shoot.
I assume your not a benchrest shooter or have a benchrest rifle or are using custom made bullets, in that case don't waste your time weighing cases.
Here's what you can do that can improve group sizes, this is assuming your a decent bench shooter with a good bench and rest, and your not shooting off your car hood over a rolled up jacket.
Do your absolute best at reloading how many ever cases you want to sort for quality of group, number every case one to whatever, say 100 cases, find a box that will hold how many ever that is, mark the spaces to correspond with the cases. Those cases live in those spaces from now until they're thrown away, they may leave to be shot or reloaded but that's where they belong.
You'll need a chronograph for the next part, shoot them in order in lots of 5 or 10 depending on cartridge, record the velocity from each case and where it landed on the target.
It'll be obvious when you come across a case that for whatever reason makes bullets land out of the normal grouping usually due to out of normal velocity, that's assuming your bullets have good run-out or your not shooting an innacurate bullet or one not appropriate for twist or a million other little things that can go wrong.
People will argue this all day but case manufacturer matters, I get the best groups from Lapua and Norma. Remington and Winchester are fine for hunting accuracy but if you want to see how good your gun really shoots use Lapua.
Here's what you can do that can improve group sizes, this is assuming your a decent bench shooter with a good bench and rest, and your not shooting off your car hood over a rolled up jacket.
Do your absolute best at reloading how many ever cases you want to sort for quality of group, number every case one to whatever, say 100 cases, find a box that will hold how many ever that is, mark the spaces to correspond with the cases. Those cases live in those spaces from now until they're thrown away, they may leave to be shot or reloaded but that's where they belong.
You'll need a chronograph for the next part, shoot them in order in lots of 5 or 10 depending on cartridge, record the velocity from each case and where it landed on the target.
It'll be obvious when you come across a case that for whatever reason makes bullets land out of the normal grouping usually due to out of normal velocity, that's assuming your bullets have good run-out or your not shooting an innacurate bullet or one not appropriate for twist or a million other little things that can go wrong.
People will argue this all day but case manufacturer matters, I get the best groups from Lapua and Norma. Remington and Winchester are fine for hunting accuracy but if you want to see how good your gun really shoots use Lapua.
Interesting opinions on case volume and weight. There's another variable in loaded cartridges that when measured the traditional way the cartridge is positioned differently to the measuring device than it is in the chamber.
No commercial bullet runout gauge orients the bullet to the dial indicator like bottleneck cartridges align their bullet to the bore center when fired.
No commercial bullet runout gauge orients the bullet to the dial indicator like bottleneck cartridges align their bullet to the bore center when fired.
I am handloading for accuracy to find the best load for the best batch of bullets, cases, and powder combination I can find.
I don't have a benchrest rifle but use the same technique in almost all my firearms. In fact, I weigh pistol brass too sometimes if I want to make load that I shoot clay pigeons at 100 yards. I should shoot at a target someday to see what kind of group I get. Getting back to rifle cartridges. I resize all the rifle range brass on an electronic scale and come up with a bell curve. I might use the outliers or toss them. The majority of the brass that is on the center of the bell curve, I save for target use. I plan to use the others for hunting and practice. Discovering case volume grouping, I was thinking of breaking down brass into a more refined group. After fire-forming, I neck size with a custom Lee Collet die, expand the neck with a mandrel and turn the necks. Since I started casting, I have an okay set of mandrels now. And so, for the very best brass, I was planning to expand the necks to just under the bullet diameter by .001". I know this isn't a benchrest rifle but I'm trying to make the best cartridge possible. Afer I seat bullets, I turn the cartridge to find the high spot and mark the case. Traditional archers believe that the arrow is more important than the bow. My goal is not to shoot benchrest groups. Only the best the rifle can shoot. I want to try shooting at a target at 500-600 yards. After I find my petload and practice I like the idea of going out the field and shoot at clumps of dirt or whatever from different angles and distances. I think this will make me a better with the rifle.
I don't have a benchrest rifle but use the same technique in almost all my firearms. In fact, I weigh pistol brass too sometimes if I want to make load that I shoot clay pigeons at 100 yards. I should shoot at a target someday to see what kind of group I get. Getting back to rifle cartridges. I resize all the rifle range brass on an electronic scale and come up with a bell curve. I might use the outliers or toss them. The majority of the brass that is on the center of the bell curve, I save for target use. I plan to use the others for hunting and practice. Discovering case volume grouping, I was thinking of breaking down brass into a more refined group. After fire-forming, I neck size with a custom Lee Collet die, expand the neck with a mandrel and turn the necks. Since I started casting, I have an okay set of mandrels now. And so, for the very best brass, I was planning to expand the necks to just under the bullet diameter by .001". I know this isn't a benchrest rifle but I'm trying to make the best cartridge possible. Afer I seat bullets, I turn the cartridge to find the high spot and mark the case. Traditional archers believe that the arrow is more important than the bow. My goal is not to shoot benchrest groups. Only the best the rifle can shoot. I want to try shooting at a target at 500-600 yards. After I find my petload and practice I like the idea of going out the field and shoot at clumps of dirt or whatever from different angles and distances. I think this will make me a better with the rifle.
Full length sizing bottleneck cases setting the case shoulder back a couple thousandths has been the norm for best accuracy since the late 1950's. Case necks are best centered on the case shoulder and straight on the case.
Dies don't have the expander ball but their necks are honed out to a couple thousandths less than a loaded round neck diameter. Or full length bushing dies are used.
Dies don't have the expander ball but their necks are honed out to a couple thousandths less than a loaded round neck diameter. Or full length bushing dies are used.
Last edited:
lol , and that's all I got to say about that ( gump )
Can you elaborate on what you mean by "range brass" ?
Is this random mixed range brass you pick up ?
Are you at least separating by headstamp ?
Also is this the same brass you are weighing and reloading to get consistent reloads ?
Pictures of the cases at each stage would help because something ain't right.
Resized case vs Fireform Case
The cartridge on the left is a resized USGI 30-06 using an RCBS 7.7x58 resizing die. The case on the right is a fire formed USGI case that was initially resized, cut to length, and after fire forming, neck turned ( the brass wall is thick ). The shoulders of the resized case is not as sharp as I thought but look how much the fireformed case would be narrowed if I use the sizing die to try and bump the shoulder back.
The cartridge on the left is a resized USGI 30-06 using an RCBS 7.7x58 resizing die. The case on the right is a fire formed USGI case that was initially resized, cut to length, and after fire forming, neck turned ( the brass wall is thick ). The shoulders of the resized case is not as sharp as I thought but look how much the fireformed case would be narrowed if I use the sizing die to try and bump the shoulder back.
Last edited:
Benchrest techniques used in competition have the 13 pound rifle resting on bags untouched by human's except for a finger on the 1 to 2 ounce trigger. The rifle recoils freely and very repeatable from shot to shot. 22 and 24 caliber bullets in small cases don't move the rifle very much during barrel time.
When we hold and aim the rifle, groups show how precise we shoot them. If you ever watch a dozen people shooting a 5 shot group shouldering a 12 pound 308 Win scoped match rifle with a 2 pound trigger resting on bags atop a bench then see groups at 100 yards ranging from 1/2 to well over 2 inches, you'll understand.
Last edited:
burgbank_jung
Lot of shooters use BR technique including F-Class Open which Bart hasn't comment on.
http://bulletin.accurateshooter.com/2017/12/competition-hardware-the-modern-f-open-rifle/
This good article from Bryan Litz on how he prep his brass and shooting almost free recoil.
http://bulletin.accurateshooter.com...irst-ever-f-tr-match-with-pierce-built-rifle/
Lot of shooters use BR technique including F-Class Open which Bart hasn't comment on.
http://bulletin.accurateshooter.com/2017/12/competition-hardware-the-modern-f-open-rifle/
This good article from Bryan Litz on how he prep his brass and shooting almost free recoil.
http://bulletin.accurateshooter.com...irst-ever-f-tr-match-with-pierce-built-rifle/
Follow the advice of Litz and Erik Cortina and you can't go wrong. I am a disciple of both. I started shooting F class 3 years ago and while I do not claim to be in their league I practice their "simple works" reloading practices.
Here is one of my 800 yard scorecards just to show that simple case and reloading is effective for me. The Peterson brass used in this match is on it's 11th reloading. It was cleaned, sized with a Redding bushing die, primed with a RCBS bench primer, chamfered. Powder was measured on a RCBS Chargemaster and checked to make sure it was within .1 grains. Berger 105 Hybrids were seated using a Lee 4 hole turret with a Redding seating die. No annealing, measuring or sorting of bullets or cases was performed
Here is one of my 800 yard scorecards just to show that simple case and reloading is effective for me. The Peterson brass used in this match is on it's 11th reloading. It was cleaned, sized with a Redding bushing die, primed with a RCBS bench primer, chamfered. Powder was measured on a RCBS Chargemaster and checked to make sure it was within .1 grains. Berger 105 Hybrids were seated using a Lee 4 hole turret with a Redding seating die. No annealing, measuring or sorting of bullets or cases was performed
Attachments
Last edited:
Handloaders use benchrest techniques for their non-benchrest rifles to improve the accuracy of their handloads. The Shooting Community is indebted to benchrest shooters for the techniques they developed. It's not that most shooters want to be like a benchrest shooter without the expensive rifle but have the best or better than needed handload for their rifle and acquire better than expected results. For example, my first rifle was an Enfield with a non-gunsmithing scope mount that shot 1" groups at 100yards. I was only separating brass by headstamps. The Arisaka shoots better. No disrespect to benchrest shooters, if a non-benchrest shooters is asking for information, he's picking your mind for your knowledge.