7 X 57 with cast
- Thread starter Ben
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Joe7436
Member
Yes talking about shooting cases that all have the exact same internal capacity. They can have same internal capacity, but yet have different case weights which doesn't make a difference then. Weighing cases can help to a degree, same internal capacity is the ultimate. Watch those ES's and SD's between the two.
If the internal capacity is the same and the weight varies a bunch then where is the extra brass? All trimmed to same length, all uniformed primer pockets, all new unfired brass. The extra brass isn't on the outside of the case of they are full length resized.
Again, the OP is talking about a 30 gr difference, not 1 or 2 grains.
Again, the OP is talking about a 30 gr difference, not 1 or 2 grains.
Joe7436
Member
It's a thread drift Brad, get over it. I explained where most the brass difference is with my friends visit to the Hornady brass factor. Those CNC machines that finish the head and extractor groove have a min/max tolerance. That's where brass goes. If it varies by a "bunch" it would be interesting in seeing what the internal capacity of those "bunch" ones are. I will have to say that much difference in weight in the same name brand case would get my attention. I would take the odd balls and section them, and also one of the heavier ones on the other end of the scale, and compare them. Would lead me to believe the lighter ones have a much thinner wall. This is easy to see in what I consider el cheapo brass like Aguila ammo and also some CBC I had in 45 acp. Yes I know not rifle brass, but I sectioned them and what I saw caused me to toss them.
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Ok, brass has a density of .13gr/mm^3
Even a 15 gr difference works out to be 113 mm^3. If the extractor groove is that loose on tolerance then something is amiss.
Yea Joe, I understand thread drift. What you stated wasn't thread drift at all. You said weighing cases was pointless. Seems to me that in this case it was very useful. A member noticed a problem and he searched for a solution. Turns out that he found brass that was of a couple obviously different thicknesses.
Even a 15 gr difference works out to be 113 mm^3. If the extractor groove is that loose on tolerance then something is amiss.
Yea Joe, I understand thread drift. What you stated wasn't thread drift at all. You said weighing cases was pointless. Seems to me that in this case it was very useful. A member noticed a problem and he searched for a solution. Turns out that he found brass that was of a couple obviously different thicknesses.
Joe7436
Member
Brad a knowledgeable reloader would have caught such a huge discrepancy as that. I'm talking once you reach that level weighing cases is the wrong method, even though it will work so some degree. Internal capacity is the ticket. What Bret has is very unusual and yes that's not an extractor/head problem. I'm convinced it's thin brass. I've wondering if they are even out of the same lot.
Bret? Bret didn't post about the brass, Khornet did. He is a quite knowledgable reloader, he has been doing it since the 50s.
I gave him those cases. They were given to me by a person who got them straight from Hornady. They are from ammo that was pulled from the loading one for quality control inspections. The guy I got it from had a son who was an engineer for them at the time. He told me that Hornady didn't make their own brass at the time, it was outsourced. Wouldn't amaze me at all. I have many boxes of Hornady seconds bullets that have different canalure locations or nose shapes than Hornady bullets. These are from runs they made for Win or Remington.
Are for internal capacity. That is essentially what we are measuring with case weight. Might not be perfect but it is quick and easy. It certainly let's us sort out the garbage cases.
Joe7436
Member
Brad I've seen so many experts or knowledgeable people in various fields screw up major. The difference between a master and a beginner is that a master has failed way more times then the beginner has ever tried.
Sorry about the over look on who posted that. All I can say is it wouldn't happen to me and never has happen to me.
Hornady should have paid attention more even if they were outsourcing. You know Hornady started as a precision shooter as did Speer. Do you think if I had a company like them that I wouldn't be paying attention??? You better believe I would.
Let me ask you Brad, when you have your cases in the loading tray primed and powdered up don't you look and get curious why the powder levels are not all the same? With brass that has a difference of 30 or more grains would definitely so a level difference. I dump the powder and start an investigation.
Sorry about the over look on who posted that. All I can say is it wouldn't happen to me and never has happen to me.
Hornady should have paid attention more even if they were outsourcing. You know Hornady started as a precision shooter as did Speer. Do you think if I had a company like them that I wouldn't be paying attention??? You better believe I would.
Let me ask you Brad, when you have your cases in the loading tray primed and powdered up don't you look and get curious why the powder levels are not all the same? With brass that has a difference of 30 or more grains would definitely so a level difference. I dump the powder and start an investigation.
Well; I am reading this conversation and hear that case weight means a whole lot and someone else says it means nothing and there are several reasons why on both sides. I Have a theory that I haven't seen there exactly and it is how I think so I joined and am going to muddy the water some with my understanding or misunderstanding. So I am going to join your group since I see several level heads that are interested in many things that interest me.
The Rifle is Chambered in a caliber by removing some amount of metal and it has a fixed volume If I put a heavy weight case in that chamber I will have my bottle to hold the powder, sealed with a bullet, the primer holder sealed by a primer and the gasket that stops it from leaking. My usable volume of that chamber is less than if I had used a lighter weight case, More brass in the case takes up more space in the chamber. The case weight causes the effective chamber volume to vary, so I believe uniform case weight is how we get uniform chamber volume and that is what is important so we have uniform pressure at firing. We start out with a chamber that is perfect since it is used for each cartridge and we put a case in that chamber that is lighter or heavier than another one at the moment of firing. The volume is established by the size of the chamber and the case has conformed to the chamber and done it's job as a gasket by sealing to the chamber walls and released the bullet. If we resize the the case to factory spec's it can be fired in another chamber and have a different volume. As brad said if the weight is different and the volume is the same where did the extra brass go.
I hope this is clear, the more I read it the more I feel that it is not but I don't know how to make it better and hope I don't sound like a know it all. Yep this country boy is in over his head. In any size case I sort by weight more than head stamp and use about 5 grains as the limit for each batch of 308 size cases to get what I call factory equivalent loads. More demanding types of ammo get narrower limits and more things done to them. I can't see an extractor grove varring by 30 grains and every company no matter where that brass is made, In house or outside contracts will have variations from lot to lot and the range of variations will change every time there is a die replaced or sharpened or polished. Brass alloys even vary some. If any test is done to determine the changes with cases before and after cutting the extractor grove or any other action it has to be done with the same lot of brass or it is of no value. I understand that lot numbers can change from just a machine adjustment depending on what it affects and always change when dies or punches are changed. Now this is only taking into account 1 method of manufacturing (extrusion or drawing), If cases are from different methods all values must be rerun but major changes to the machines or methods still make major changes to the product.
Thanks for listening
R D
May GOD bless you and yours
The Rifle is Chambered in a caliber by removing some amount of metal and it has a fixed volume If I put a heavy weight case in that chamber I will have my bottle to hold the powder, sealed with a bullet, the primer holder sealed by a primer and the gasket that stops it from leaking. My usable volume of that chamber is less than if I had used a lighter weight case, More brass in the case takes up more space in the chamber. The case weight causes the effective chamber volume to vary, so I believe uniform case weight is how we get uniform chamber volume and that is what is important so we have uniform pressure at firing. We start out with a chamber that is perfect since it is used for each cartridge and we put a case in that chamber that is lighter or heavier than another one at the moment of firing. The volume is established by the size of the chamber and the case has conformed to the chamber and done it's job as a gasket by sealing to the chamber walls and released the bullet. If we resize the the case to factory spec's it can be fired in another chamber and have a different volume. As brad said if the weight is different and the volume is the same where did the extra brass go.
I hope this is clear, the more I read it the more I feel that it is not but I don't know how to make it better and hope I don't sound like a know it all. Yep this country boy is in over his head. In any size case I sort by weight more than head stamp and use about 5 grains as the limit for each batch of 308 size cases to get what I call factory equivalent loads. More demanding types of ammo get narrower limits and more things done to them. I can't see an extractor grove varring by 30 grains and every company no matter where that brass is made, In house or outside contracts will have variations from lot to lot and the range of variations will change every time there is a die replaced or sharpened or polished. Brass alloys even vary some. If any test is done to determine the changes with cases before and after cutting the extractor grove or any other action it has to be done with the same lot of brass or it is of no value. I understand that lot numbers can change from just a machine adjustment depending on what it affects and always change when dies or punches are changed. Now this is only taking into account 1 method of manufacturing (extrusion or drawing), If cases are from different methods all values must be rerun but major changes to the machines or methods still make major changes to the product.
Thanks for listening
R D
May GOD bless you and yours
Case capacity can make a huge difference in load pressure and ballistics. BUT here's a simple way to think about it -- variation in case capacity makes big difference in high pressure loads, and makes very little difference in low pressure loads. What does this mean? It means that I religiously sort my .308 brass that I will use for high pressure hunting loads (where the case can make as much a 4.0 grain difference in the powder charge), but I don't bother sorting the .223 brass that I use for low pressure small game/varmint cast bullet loads.
Glen I see what you are saying but i wonder about Ignition of the powder in the varying capacity of the small charges and large cases. I know I may be trying to over think this but in reading about low power loads on the Gun Writers of The Web and others It seemed that The single largest problem to consistency and accuracy was ignition. This is a new subject of interest to me since being medically retired and I found some people used only magnum primers to assure full ignition where on here many use standard pistol primers. I have reloaded since 1968 but just not this style load. I Hope to soon get over these shakes and restart hand loading so I wish to understand as much as I can because I want to start on this type load.
Thanks for listening
R D
May GOD bless you and yours