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rmatchell
12-31-2012, 11:34 AM
So as I have said before I am still working on building up my load data but I keep running into problems with boolits. I use almost all coww right now and depending on the mold everything cast 5 to 10 grains heavy if you go by what the maker posts. Point in case I got a lee 356-120-tc that cast out to 127 to 130 gr most of the time ill just use jword data backed down for the same weight if its is available as so far no problems every now and then I cant find the right data. My real question is am I right to assume that boolits with the same weight as jword will have less pressure and that a reduced load will give me the same results? I only really get worried when I know im getting close to the upper limits.

RobS
12-31-2012, 11:45 AM
Cast boolits will typically give you less pressure than a jacketed of equal weight/length. I would just start at the lower end/middle of the load data and work up for accuracy; many times the upper end loads will not be the most accurate anyway.

Larry Gibson
12-31-2012, 12:00 PM
Your COWWs have more lead in them and less tin than the alloys used when the designs were made, thus your bullets will be heavier as they are. You will get a better alloy if you simply add 2% tin to your COWWs thus giving a better tin to antimony % which will allow them to blend into the lead in a better solution. You will get better castings with less rejects, slightly larger diameter and an increase in BHN to 14 - 17. All that and slightly less bullet weight.

Larry Gibson

rmatchell
12-31-2012, 12:39 PM
Thanks for the reply guys, I guess what I really ment was the upper limits on the weight side. Good example I have a lyman 311359 that I would love to use in my 30 carbine but it cast at 128 I haven't been able to fine load data for that heavy of a boolit.