empty case weight?

Pitt55 · Posted: Thu Aug 09, 2007 9:31 pm Post subject: empty case weight?

I have never really weighed my empty cases until tonite and found it very interesting. On the 300mag cases from Remington the range was 268 to 275 gr. On 243win. cases from Remington less than 1gr. spread. I also found Winchester brass to be worse than Remington. I guess what I'm asking is do you guys find these numbers as well? Also what do you allow for spread in say a box of 20 rounds when loading for hunting? What are you guys finding with the brands you all use? Maybe a guy has to go to nosler for brass. Their website says each batch is sorted by weight.
DON

Vince · Posted: Thu Aug 09, 2007 11:27 pm Post subject: Re: empty case weight?

Interesting topic Don.

I can imagine that there could be a couple of different reasons why cases would vary in weight:

the alloy mix in the brass,
the thickness of the case wall,
the thickness of the case web,
the overall dimensions of the case.

I know that each and every part/section of a case has a "blueprint" measurement, but these can and do alter...which can affect overall weight. However, I don't see that weight of the case is a significant factor unless you are into shooting disciplines like Benchrest. I suppose that a thicker case wall will cause slightly higher pressures compared to the same load in a case with thinner walls, but I don't believe that this increased pressure would be a concern unless you are loading maximum charges of powder and mixing brands of cases without checking dimensions.

Soooo....no, I don't weigh my hunting cases...don't see a need for it. I use only Remington brass in my .243 and Winchester brass in my 30.30 Mod 94.

Any of the more experienced and exacting handloaders out there feel free to set me straight if the above is not entirely correct. Very Happy

Cheers, Vince

Handloader · Posted: Fri Aug 10, 2007 12:32 am Post subject: Re: empty case weight?

Remington, Winchester or Norma, out of 100 cases, some will weight variation will occur. As mentioned by Vince, unless one is striving for the utemost accuracy, case weight variation, within some limits, will have no significant effect.

As a matter of routine, I seperate cases that have a deviation of more than 3% weight. In that process I will often find some cases that are significantly lighter or heavier with as much as 8% deviation. Other aspects of case prep probably warrant more attention, such as primer flash hole deburring, trimming and chamfering.

Nosler brass is amazingly good, but, pricey. In fact, it is so uniform, IME, that one can load it directly from the box. No need to prep. One can justify its cost on a time based consideration, however, in most cases I enjoy the whole case prep process.

Deleted_User_2665 · Super Member Joined: May 06, 2006 Posts: 380

If you are looking for sub MOA groups from hunting loads in a standard hunting rifle, off the shelf with little tricking done other than quality glass and a smooth trigger.......then case weight variations don't mean chitt.

Load OCW and rule the world...........

SwampFox · Posted: Fri Aug 10, 2007 7:43 am Post subject: Re: empty case weight?

The weight of the empty case as a final result has absolutely nothing to do with consistant velocity or accuracy. The cartridge case is a container. As with all containers, the volume of the container is the critical portion of the formula, not the exterior size or the weight of the container. You should not use the empty case weight as anything but a step in the case preperation process.

When you do case preperation, the proper end result of the exercise is the determination of case volume, anything else is incorrect and a waste of your time.

If you doubt what I am saying here, trim, load and fire 50 cases, then weigh the 50 fired, primed, unsized, cases. The cases are consistant to your chamber deminsions. Segregate the cases into groups by weight.

Now select 10 cases that are the same weight, fill the 10 cases with water, weigh again, deduct the empty case weight, now you have a volume measurment. If the weight of the empty case gave you the correct final answer, the volumes would all be the same, right? Guess what, it will not be so. Now go back and do the lot of 50 again by volume. You will find a whole new set of brass with the same volume but different case weights. Guess what again, the majority of the same weight cases will not be in the same volume group!

This was part of a magazine article that I wrote and that was published about precision reloading. None of the above is an opinion, I have done the test at least a dozen times and the test always comes out the same.

Guys, if you want to shoot the best groups you can, you must have precision loads and the only way to accomplish that is with precision loading practices.
Ed

ElyBoy · Posted: Fri Aug 10, 2007 3:03 pm Post subject: Re: empty case weight?

I agree with Vince and the guys. Unless you are shooting bench rest, don't worry about it.
There are enough things to consider when pulling down on game, without thinking how much the brass weighs.
If my right leg weighs more than my left leg, I might veer to the right when walking a straight line. THEREFORE, I should put weights in my right shoe to walk a straight line. Sad

What the hell am I talking about. It must be the heat. wtf

Eric

hunterjoe21 · Posted: Fri Aug 10, 2007 3:42 pm Post subject: Re: empty case weight?

ElyBoy wrote:

If my right leg weighs more than my left leg, I might veer to the right when walking a straight line. THEREFORE, I should put weights in my right shoe to walk a straight line. Sad

What the hell am I talking about. It must be the heat. wtf

Eric

Wouldn't your right foot drag even more, act even more like an anchor, and cause you to spin almost uncontrollably? (to the right)

Perhaps a BEER in your LEFT hand would counteract this and put you back on course.

Deleted_User_2665 · Super Member Joined: May 06, 2006 Posts: 380

SwampFox wrote:

The weight of the empty case as a final result has absolutely nothing to do with consistant velocity or accuracy. The cartridge case is a container. As with all containers, the volume of the container is the critical portion of the formula, not the exterior size or the weight of the container. You should not use the empty case weight as anything but a step in the case preperation process.

When you do case preperation, the proper end result of the exercise is the determination of case volume, anything else is incorrect and a waste of your time.

If you doubt what I am saying here, trim, load and fire 50 cases, then weigh the 50 fired, primed, unsized, cases. The cases are consistant to your chamber deminsions. Segregate the cases into groups by weight.

Now select 10 cases that are the same weight, fill the 10 cases with water, weigh again, deduct the empty case weight, now you have a volume measurment. If the weight of the empty case gave you the correct final answer, the volumes would all be the same, right? Guess what, it will not be so. Now go back and do the lot of 50 again by volume. You will find a whole new set of brass with the same volume but different case weights. Guess what again, the majority of the same weight cases will not be in the same volume group!

This was part of a magazine article that I wrote and that was published about precision reloading. None of the above is an opinion, I have done the test at least a dozen times and the test always comes out the same.

Guys, if you want to shoot the best groups you can, you must have precision loads and the only way to accomplish that is with precision loading practices.
Ed

If you are looking for sub MOA groups from hunting loads in a standard hunting rifle, off the shelf with little tricking done other than quality glass and a smooth trigger.......then case weight variations don't mean chitt.

Neither do differences in case capacity........

Load OCW and rule the world...........

ElyBoy · Posted: Fri Aug 10, 2007 7:18 pm Post subject: Re: empty case weight?

A beer in BOTH hands, and I wouldn't care what direction I went in. Insane

Eric

Deleted_User_2665 · Super Member Joined: May 06, 2006 Posts: 380

I've images uploading as I type, of a bit of Rifle Work I did this afternoon with my 30-06.

Have been testing a swap load, which would have come in the other thread if some numbnut hadn't over moderated the other thread, a swap load with 168 grain X's and 168 grain Hornady Match.....

I'll post that pic in a few minutes as it relates to this thread...........

Deleted_User_2665 · Super Member Joined: May 06, 2006 Posts: 380

Got some results to show you from my work with a 168 grain swap load.

Been looking for 168 TSX's and 168 Hornady Match to hit same point of aim and have been coming up with a goodly OCW load in that regard.

This is only at 100 yards so until I confirm at 300 it really don't mean shitt....but it's got promise.

Imaged here are two groups, one with the X's and one with the Match. Three shots fired at each spot, all from a cold barrel.

Each group has one of each powder charge of Reloader 19....59.2, 59.4 and 59.6 grains.

I came up with that range through other testing and it seems that there in lies the sweetspot per OCW.

I'm going to consider the 59.4 charge as Optimal and do further testing with that charge alone.

"Groups" will be "tighter" with the one single charge weight and any further adjustment can be made with slight tweaks of seating depth.

As you can see now though, even though there are differences in charge weight, hench differences in pressure, there are still MOA groups shown here...both hitting the same POA, give or take, with the 59.4 charge being the closest with both bullets.

That tells me many varibles can be overlooked (to a point) and this "load" is pressure difference tolerant.

Differences in case capacity, which is some of the Voodoo some folks like to worship, unless, grossly overstated, are of little consequence as they translate ONLY into a difference in pressure exerted on the bullet, hence an increased or decreased speed.

Loading with the OCW principles negates much of that Voodoo...............

PaulS · Posted: Fri Sep 21, 2007 3:47 am Post subject: Re: empty case weight?

The weight of the case can make a difference in the pressure and, as a result, the acuracy of your ammunition. Lets say you only neck size your brass. All of your brass is sized to the chamber of your rifle due to having been fired at least once. If the external dimensions are all the same and you have some brass that is 64 grains and others that are 75 grains then the only way that can happen is if the lighter cases have more volume on the inside. The load that you use will fill the heavier cases more than the lighter cases. The extra space in the lighter cases means that there is less pressure generated when they are fired. Those shots from the lighter cases will be slightly slower than the heavier cases because of the reduced pressure. a slower bullet will drop more over a given range than a faster bullet so your groups will reflect that as larger groups. If all your brass is within a half grain of each other, the difference is less and your groups will be smaller. If you happen to work your load up in the larger cases and you shoot at maximum pressures then the heavy cases are going to go over that maximum pressure causing shorter case life and higher than maximum pressure in your gun. Over time that may or may not cause problems but it could cause problems when going from cold weather to hot weather shooting.
I segregate my brass into three groups. The lighter cases, those that are in the middle and those that are heavy. You will get about 10% high and 10% low leaving you with 80% in the middle range (in each lot). The median weight may change from lot to lot but it will almost always yield about 80% of the brass in that lot. You still have to adjust your load to each lot to get the best performance from it.

Vince · Posted: Fri Sep 21, 2007 4:00 am Post subject: Re: empty case weight?

Gidday PaulS....long time no see mate.

Cheers, Vince

GroovyJack · Member Joined: May 21, 2005 Posts: 621 Location: Bama

I think everything mentioned here plays a difference , if your cases are all trimmed to the same length and are different weights , the only difference can be the interior / exterior dimensions are different .. Now you have combustion chambers of varying capacitites firing the same charge .. The pressure has to be different ..

Do it matter ?? Yes and no ..
For one we commonly load cases with a powder charger that varies the powder charge by a fair bit each throw .. Still make small groups ..
Unless I were benchshooting , did but no more , I wouldnt worry about it too much .. As a matter of course I never give it a second thought .. But there are other things I do that some handloaders dont ..

It's a mindset , we each have our routine and we hate to alter it .. If you approach reloading with the right mindset , when you pull the trigga , you will confidently say you did the best you knew how to , and if you shot a tiny group or a nice buck or whatever , then your confidence in what you did is increased ..

K.W. · Posted: Fri Sep 21, 2007 5:03 am Post subject: Re: empty case weight?

If You make test shooting with Yours best cases and put those in the "same hole hit" cases in own box and others in other box too. Nex time all cases are not in the same boxes. I mean: To day accurate case are not necessarily accurate to morrow.