Author Topic: Case weights? (Read 499 times)

Trapper-Jack · « **on:** January 23, 2005, 08:16:41 AM »

I've read that some of you "hard core" BPCR reloaders will weigh the cartridge cases based on the theory that if the outside dimensions are the same with the same weight, the inside will all be the same, hence the compression of the same amount of powder will be the same. I have quite a number of R-P brass that I bought all in one package that will vary as much as 20 grains from heaviest to lightest. Then I have some W-W brass that will weigh lighter yet. Keeping the same headstamps together, how close is close enough to group the weights of the brass? Within a couple of grains? +/- 5 grains? +/- 10 grains?

I've read quite a bit about grouping the bullets into groups +/- .5 grains with the really serious ones going +/- .10 grain. The only thing I've read about grouping the brass is one post stating they grouped them "light", "medium" and "heavy".

fffffg · « **Reply #1 on:** January 25, 2005, 06:02:58 PM »

i use 1 grain sepparation aprox.. i now use a gram scale and its .1 grams. you can go to a conversion chart and see what that is. it seems to work ok for me.. another consideration is that bp fouling buildup in the case doesnt weigh much and will decrease case size. pwderburner started me with cleaning cases with wire brush like from bore brush.. i put one on a drill. lot more work but seems to pay off.. as you said hardcore.. but what else have i got to do on a cold night in montana? good luck, dave..

Trapper-Jack · « **Reply #2 on:** January 26, 2005, 12:51:08 AM »

Thanks for the reply. I'll try the wire brush and see what it does for me. I used to use a 3/8 dowl with a bit of steel wool on the end of it chucked in a drill but lately all I have been using is a small bottle brush when I clean up the cases in soap and water after I've punched out the primers, and then put them in the vibratory case cleaner. Maybe I need to go back and polish the insides a little more. Have you seen a differance in the results of mixing headstamps as long as the weights have been the same?

powderburner · « **Reply #3 on:** January 26, 2005, 04:59:29 AM »

Hey there Trapper Jack ,
while reading your post I came up with a couple questions.
1 are your cases weighing +-20 new or fired?
are you still getting black out down deep by the head?
I had a batch of R-P cases (500) and the whole batch only varied 4 gns so your numbers seem excessive ,the volumes of the cases are dependant on the conctruction of the case wall thickness web thickness and such . for just shooting not much matters other than you use the right components . When you start shooting for accuracy that is when you will find with black powder that consistancy is the thing . 1/2 gn bullets, neck tension ,case weight ,primer selection,overall length ,seating depth, and many more variables.
to maintain a smooth release of your bullet your case necks should be as clean and shiny as possible.this also has a good side effect as it keeps your cases from separating in the chamber on you , Cleaning the cases til they are shiny inside all the way to the head is good as it maintains a consistant volume in the case and it gets the corrosive junk out of your cases.

All this said you should keep your cases segregated at least by manufacturer and in a minimum af 2-3 gns weight for consistant case charging. the internal capacities of winchester brass has always been larger than R-P brass by 2 or 3 gns wt.

a simple test is to take a known measure and fill it to the brim with 3 f or something similar and then dump it in a few different cases and see how the volumes vary. or weigh a smaller charge and pour it (the one charge) into different cases the same way each time and measure the height in the case hope this helps...............Dean

Ray Newman · « **Reply #4 on:** January 26, 2005, 09:32:11 AM »

Trapper-jack: what I found to work well for me is that after decapping, take a small plastic mallet & give the case hard, sharp rap or 2. A good deal of BP residue will drop out.

Then follow up w/ a stiff nylon bore brush attached to the mallet handle to brush out the case. I found that the more residue that you removed prior to washing, the better.

I would be a bit leery of using a bore brush on an electric drill-- any danger of scoring the case whereby the wad could drag & stretch the case & eventually case separation?

From what I read the ceramic media seems to be the catÂ’s meow for cleaning cases & it even cleans the primer pockets. From what IÂ’ve been told, if you have a vibratory case cleaner w/ a tight fitting lid, the media still can be used, you just canÂ’t clean as many cases @ once as w/ other cleaners, such as a tumbler. I havenÂ’t heard one of user who was dissatisfied w/ the media method. ItÂ’s next on my to get listÂ….

Trapper-Jack · « **Reply #5 on:** January 26, 2005, 02:55:24 PM »

Thanks to everyone that replied. You have given me some things to think over. After I've cleaned my cases I've noticed that the insides are not as shiney as the outsides and didn't give it a thought as the powder column appeared to be the same after the powder was dropped in. I may be getting a little different amount of drag on each of the bullets and can improve on my accuracy if I put a little more effort on the insides. Most of the R-P brass that I have I bought in one bunch of 250. Some of them weigh around 190 grains each and others are going about 170. Maybe I got a break point between two different lots.

My kids gave me some W-W brass for father's day. I haven't gotten into many of them, only about a half dozen, just to see how they loaded and shot. Those have weighed a little lighter than the lighter R-P's. I also noted that when I charged them next to the R-P's, the powder column was lower in the case with the same amount of powder, hence the larger capacity.

Again thanks for the replys. I will group my brass up as closely as possible after a good cleaning inside. I was wondering what most of you used for a cut off point. I would like to develope some loads for the mid-range 200-500 meter steel targets. It now makes sence to me to group my ammo in lots of what will be shot at each different range.

I've also heard and read about the ceramic media. Everything has been good and no negative comments. I think I'll look into that too.

fffffg · « **Reply #6 on:** January 26, 2005, 03:32:22 PM »

Ray, no scratching is found with magnifiying lens at all. the only marks are from expander going directly in and out. sacrafice a case, and try a bore brush after your cleaning methods, you might be surprised at how much fouling is still in the case.. i have a very few cases. about one hundred and shoot the same 40 of those all the time.. only case loss is from crushing by not putting all the way into the press or some such.. we all need to try some new methods some times.. you might be pleasently surprised.. if we dont try new things, we cant improve.. good luck dave.

Ray Newman · « **Reply #7 on:** January 26, 2005, 05:58:03 PM »

"if we dont try new things, we cant improve"

Thta's why I'm moving on to ceramic media....

powderburner · « **Reply #8 on:** January 27, 2005, 03:39:24 PM »

trapper ,got your e-mail but am tangled up with my server when I get straight Ill get back to you ....Dean

Lead pot · « **Reply #9 on:** January 27, 2005, 04:04:13 PM »

I use only ceramic media now for black powder cases. they shine like new cases on the inside and outside. and primer pockets are clean.
I used to use a test tube brush with soapy water to clean the inside. This is the only way to go.
When you reload a dirty case it will stetch excessively and separation is more frequent.
I sort my cases with one halve grain tolerance.

Kurt