aliceinchains
04-27-2004, 07:46 PM
As dig stuff up off the internet , i like to share it here. And here is an excellent example.
I started to make my own brass because I lost most of my expensive Norma brass on the second firing; I would not have minded the cost of the Norma brass if I got reasonable case life with it. In defense of Norma, I believe that if I had just necksized only with their brass after the first firing and kept the cases separated for each rifle, I would have gotten better caselife with them.
Here goes, I am including perhaps more details than necessary, but I do not know how much experience you have with forming cases.
All you need is a set of full length sizing dies and a case trimmer, you could get by with just a trim die and not have a case trimmer, I invested $200 in a power case trimmer but I have other uses for it (and I was starting to show symptoms of Carpal Tunnel from cranking the manual case trimmer I have been using for about 20 years).
Remove the decapping pin/expander ball assembly from your FL sizing die and put the die in your press, set it about 1 turn from touching the shell holder, lightly lube the case with a good case lube (I like Imperial Die Sizing Wax, once you try it you will never go back to what you were using) and press the case part way into the die, do not try to size it completely in one shot. Remove the case and relube it, size it again a little deeper into the die, remove and relube it again and finish sizing it (if you see small dents in the shoulder, you are using too much lube). Now take your 6.5mm rifle, remove the striker assembly and try it in the chamber, the bolt should not close. Turn the FL die a little closer to the shell holder (1/8 turn or so), relube the case, size it and try it in the chamber again. Keep repeating this process of sizing a little more and trying the case in your rifle until the bolt will just close with slight resistance.
I know that this may sound like a lot of work, but what you are doing is setting the shoulder of the case to headspace perfectly in your rifle, in fact it is so perfect that this case may not chamber in another rifle, but by doing this and necksizing when you reload your brass will not stretch and your caselife will be increased.
Now take the rest of your .220 Swift brass and size them in three steps as above. You now have the shoulder formed and a short section of 6.5mm neck that tapers down to .22 caliber. Replace the decapping pin/expander ball assembly into your FL sizing die. There should still be enough lube on the outside of the case, but take a Q-tip and rub a little caselube inside of the neck of the case. Press the case up into the FL die with the decapping assembly in, this will expand the whole neck to 6.5mm., if you find this difficult and you have a 6mm (.243) or .25 rifle decapping assembly, you can put it into your 6.5mm die and do the neck expanding in two steps, however I find that I can do it in one shot.
Now all you need to do is trim the cases to length, I use 1.980 inch. The cases will have a slight bulge below the shoulder because the .220 Swift case is slightly smaller in diameter at that point than 6.5mm Japanese, this will blow out to the proper shape on your first firing. After the first firing, anneal the shoulder and neck area, in the reforming process you have worked this area quite heavily which makes the brass brittle. Anneal after every 2 to 3 firings and neck size only for longest caselife.
It might seem like a lot of work with all these partial sizings and relubeing the cases and forming the shoulder and neck as separate steps, but I tried to form the neck and shoulder in the same step and found that I crushed about 40% of my brass, likewise when I tried to use fewer than three stages to form the shoulder I got oil dents or crushed shoulders. Using the process I described here 100% survive.
I started to make my own brass because I lost most of my expensive Norma brass on the second firing; I would not have minded the cost of the Norma brass if I got reasonable case life with it. In defense of Norma, I believe that if I had just necksized only with their brass after the first firing and kept the cases separated for each rifle, I would have gotten better caselife with them.
Here goes, I am including perhaps more details than necessary, but I do not know how much experience you have with forming cases.
All you need is a set of full length sizing dies and a case trimmer, you could get by with just a trim die and not have a case trimmer, I invested $200 in a power case trimmer but I have other uses for it (and I was starting to show symptoms of Carpal Tunnel from cranking the manual case trimmer I have been using for about 20 years).
Remove the decapping pin/expander ball assembly from your FL sizing die and put the die in your press, set it about 1 turn from touching the shell holder, lightly lube the case with a good case lube (I like Imperial Die Sizing Wax, once you try it you will never go back to what you were using) and press the case part way into the die, do not try to size it completely in one shot. Remove the case and relube it, size it again a little deeper into the die, remove and relube it again and finish sizing it (if you see small dents in the shoulder, you are using too much lube). Now take your 6.5mm rifle, remove the striker assembly and try it in the chamber, the bolt should not close. Turn the FL die a little closer to the shell holder (1/8 turn or so), relube the case, size it and try it in the chamber again. Keep repeating this process of sizing a little more and trying the case in your rifle until the bolt will just close with slight resistance.
I know that this may sound like a lot of work, but what you are doing is setting the shoulder of the case to headspace perfectly in your rifle, in fact it is so perfect that this case may not chamber in another rifle, but by doing this and necksizing when you reload your brass will not stretch and your caselife will be increased.
Now take the rest of your .220 Swift brass and size them in three steps as above. You now have the shoulder formed and a short section of 6.5mm neck that tapers down to .22 caliber. Replace the decapping pin/expander ball assembly into your FL sizing die. There should still be enough lube on the outside of the case, but take a Q-tip and rub a little caselube inside of the neck of the case. Press the case up into the FL die with the decapping assembly in, this will expand the whole neck to 6.5mm., if you find this difficult and you have a 6mm (.243) or .25 rifle decapping assembly, you can put it into your 6.5mm die and do the neck expanding in two steps, however I find that I can do it in one shot.
Now all you need to do is trim the cases to length, I use 1.980 inch. The cases will have a slight bulge below the shoulder because the .220 Swift case is slightly smaller in diameter at that point than 6.5mm Japanese, this will blow out to the proper shape on your first firing. After the first firing, anneal the shoulder and neck area, in the reforming process you have worked this area quite heavily which makes the brass brittle. Anneal after every 2 to 3 firings and neck size only for longest caselife.
It might seem like a lot of work with all these partial sizings and relubeing the cases and forming the shoulder and neck as separate steps, but I tried to form the neck and shoulder in the same step and found that I crushed about 40% of my brass, likewise when I tried to use fewer than three stages to form the shoulder I got oil dents or crushed shoulders. Using the process I described here 100% survive.