HWooldridge
08-03-2009, 11:07 PM
My first post on this forum concerned my desire to workup a load my son and I could use while hog hunting. I am doing this in my old model Ruger primarily because it's here and his Colt clone isn't; in addition, my revolver will one-hole all day long with the H&G #68 cast in linotype and 7.0 gr of WW231 so I know it is capable. Based on the recommendations from those who responded, I abandoned the #68 design in favor of some 250 gr Keith-style slugs from an NEI mold that were cast some time ago and are now running 13.0 to 15.0 BHN (as checked with a Lee lead tester). If my notes are correct, these were made from a mix of 4 lbs WW, 2 ounces of 50-50 lead/tin and 8 ounces of linotype - I don't recall why; just happened to be what I put into the pot at the time. I do remember that they were dropped into water which was probably 90-100 degrees because I was casting in the shop during the summer. I always drop bullets the same way, a terry cloth towel in the bottom of a 5 gallon bucket full of water. The slugs dropped at .453 and sized at .4519; I slugged my barrel long ago and it measures .4515 groove diameter. My cylinder chambers will easily admit a .450 gage pin but a .451 pin will barely start so I'm guessing they are right at .451 (I have a full set of Class Z- toolmaker's pin gages so it's easier for me to use them than fiddle with a bore mike). Lube is standard Javelina Alox/beeswax applied with a SAECO Lubrisizer into both lube and crimp grooves.
Using this heavier boolit, I loaded 12 rounds each of 13.0, 14.0, 15.0 and 16.0 grs of 2400. The 13.0 gr looked most promising for accuracy but shot high at the lowest sight setting and although groups ran 1 to 1-1/2" at 25 yds for five shots, they started opening up and were at 4 inches by the end of the string. The other charges all ran about 4-5 inches from the beginning but the 15.0 and 16.0 gr loads did shoot to point of aim. All loads left some lead streaks in the barrel which were easily removed by a brush with one pass.
So here are my questions:
1. Is 13.0 to 15.0 BHN too wide a spread for consistent grouping and does water temp make a difference in the final alloy hardness (i.e., should I be using ice water to quench)? Conversely, would I be better off by heat treating in the oven to obtain a more even BHN rather than simply dropping directly from the mold into water? My timing while casting is pretty consistent but I'm sure there are variations in bullet temps within any batch that comes straight out of the mold.
2. Is this range of BHN too low for these charges? I located several slugs in the dirt of the backstop but they were too damaged to tell anything about skidding in the rifling.
Comments and suggestions are welcome.
Thanks, Hollis
Using this heavier boolit, I loaded 12 rounds each of 13.0, 14.0, 15.0 and 16.0 grs of 2400. The 13.0 gr looked most promising for accuracy but shot high at the lowest sight setting and although groups ran 1 to 1-1/2" at 25 yds for five shots, they started opening up and were at 4 inches by the end of the string. The other charges all ran about 4-5 inches from the beginning but the 15.0 and 16.0 gr loads did shoot to point of aim. All loads left some lead streaks in the barrel which were easily removed by a brush with one pass.
So here are my questions:
1. Is 13.0 to 15.0 BHN too wide a spread for consistent grouping and does water temp make a difference in the final alloy hardness (i.e., should I be using ice water to quench)? Conversely, would I be better off by heat treating in the oven to obtain a more even BHN rather than simply dropping directly from the mold into water? My timing while casting is pretty consistent but I'm sure there are variations in bullet temps within any batch that comes straight out of the mold.
2. Is this range of BHN too low for these charges? I located several slugs in the dirt of the backstop but they were too damaged to tell anything about skidding in the rifling.
Comments and suggestions are welcome.
Thanks, Hollis