41mag
09-08-2012, 09:55 PM
Well for a month or so I have been looking over a LOT of data on blending the right alloy for HP's, that will not only allow them to expand, but will also hold them together. There are plenty of different blends most of which simply use pure lead and a good percentage of tin, like 30-1, 25-1, and 20-1. Not to mention the Keith favorite 16-1.
My biggest issue is that I do not have a copious amount of pure, maybe a hundred pounds at most. I do however have plenty of the large Iso Cores which should last me for years. That said I have been using the calculator to try and figure out what would be the best route for me to go about getting the 1/3/96 alloy softened up to a 1.5/1.5/97 without completely exhausting my pure supply. Not to mention using up expensive tin as well.
My latest blend was poured up two weeks ago, and the hardness was checked this past Tuesday on the two week mark. It fell right in at a 10BHN on my Cabine Tree tester. The boolits I had planned on casting are the MP .452 640 using both the small and large pins. Also there is the MP version 45 270 SAA, the H&G 503, and 41 HG 258. Since these are all the Cramer type molds, I had planned on blending an alloy that would hold together first, and then sort out which pin would or might be the best. My loads for each shoot VERY well with the straight Iso Core alloy, and I was unsure about softening them up and having the groups open up. But I figured that I would start with the proven load first then adjust from there depending on how things went.
So this morning I set up my bucket full of dirt at 50yds. The wind was gusting a little but not enough to bother my shooting. I loaded up the 270 SAA first knowing that was the last ones I had used and the 7.5" Redhawk was sighted in for them. The loads used were stoked with 16grs of AA-9, in Starline cases and lit with Wolf LP primers and lubed with the Recluse method. The velocity from my revolver is just over 1100fps with this load and VERY accurate out to 75yds even. I sent five of them down range, then inspected the barrel for any signs of leading. None what so ever was noted, which made me pretty happy.
I then switched over to the .452 640 with the small HP. For these I had used a load I have been using with the Lee 452 255 RF which I found on the Linebaugh article using 13grs of HS-6. With the Iso Core alloy these actually drop at 260grs and with the 640 the small HP's drop at about 275grs and the large HP's around 265grs. My actual intent was to use the large HP's for my 45acp, but I haven't' gotten around to playing with it just yet.
So after running 5 rounds of each down range I headed down with my sifter to see how they had done. Granted the sandy loam I use in my buckets is no way close to critter matter, but it does give repeatable results which is about all I can hope for right now. I removed the screw on top and started to slowly shave off the layers of dirt until I reached the first indication of a boolit. With what little dampness there is in this dirt, usually there is a dry spot just before you reach the boolits. Very carefully I sifted the previous dirt I had removed looking intently for any sign of fractured or broken pieces of the expanded HP. None were found. So I continued to easily remove the dirt and found my first perfectly mushroomed HP. As I removed it I measured the depth at which it had stopped and found that to be 6". Just another inch or two over from that one was another and then another, all looking like I had put them through a press of sorts, to get them to look almost identical. Here are a coupe which represent for the most part every one I recovered to some extent.
These were from 25yds,
http://castboolits.gunloads.com/imagehosting/2895504c6af9e55ac.jpg
and these from 50yds,
http://castboolits.gunloads.com/imagehosting/2895504c6af9abfc0.jpg
After recovering the 5 640's I gently dug a bit deeper until the tell tale sign of another boolit appeared. Again I gently removed the dirt until the boolit fell from the sand. Again I held in my hand another perfectly formed mushroom. I dug a bit deeper and found the other 4 resting at a depth of 8".
To be honest I had figured they would have been a bit deeper than they were but I am not overly concerned as the dirt does do a good job of stopping things.
So after replacing and packing the sand back into the bucket I pulled it in closer to the 25yd mark. I wanted to see if they would hold up to a bit higher impact speed. Again I started with the 45 270 SAA as I knew it would be deeper and hopefully not booger up the others. I fired 5 for group this time. After those were done with I put up another target and loaded up 5 more of the 640's. Again I fired for group and after I was done headed out to sift them out. The accuracy was pretty darned close to what I have been getting with the other loads as well.
Once again I was VERY pleased to find not only were there 10 perfect mushrooms, but thee were no signs of any fracturing or cracking anywhere I could find on the recovered boolits.
So hopefully I will be able to find a hog in the near future to test them out on. I am not overly worried about the penetration as I know that they will neither expand nor stop as short when they hit flesh as they did in the soft sand. My purpose was to put together an alloy using the large Iso core which would readily expand and not fracture the noses off as it did so. This I have accomplished. At least with the 45 Colt. The others remain to be tested. I do have pictures, but it will be sometime tomorrow or Monday before I can get them up.
So anyway here is my formula if anyone else with some of the large Iso Cores wants to give it a try,
1.5 / 1.5 / 97
Pure Tin - .0995# or 1.6oz
Pure Lead - 4.9# or 78.4oz
Large Iso Core alloy - 5# or 80oz
My biggest issue is that I do not have a copious amount of pure, maybe a hundred pounds at most. I do however have plenty of the large Iso Cores which should last me for years. That said I have been using the calculator to try and figure out what would be the best route for me to go about getting the 1/3/96 alloy softened up to a 1.5/1.5/97 without completely exhausting my pure supply. Not to mention using up expensive tin as well.
My latest blend was poured up two weeks ago, and the hardness was checked this past Tuesday on the two week mark. It fell right in at a 10BHN on my Cabine Tree tester. The boolits I had planned on casting are the MP .452 640 using both the small and large pins. Also there is the MP version 45 270 SAA, the H&G 503, and 41 HG 258. Since these are all the Cramer type molds, I had planned on blending an alloy that would hold together first, and then sort out which pin would or might be the best. My loads for each shoot VERY well with the straight Iso Core alloy, and I was unsure about softening them up and having the groups open up. But I figured that I would start with the proven load first then adjust from there depending on how things went.
So this morning I set up my bucket full of dirt at 50yds. The wind was gusting a little but not enough to bother my shooting. I loaded up the 270 SAA first knowing that was the last ones I had used and the 7.5" Redhawk was sighted in for them. The loads used were stoked with 16grs of AA-9, in Starline cases and lit with Wolf LP primers and lubed with the Recluse method. The velocity from my revolver is just over 1100fps with this load and VERY accurate out to 75yds even. I sent five of them down range, then inspected the barrel for any signs of leading. None what so ever was noted, which made me pretty happy.
I then switched over to the .452 640 with the small HP. For these I had used a load I have been using with the Lee 452 255 RF which I found on the Linebaugh article using 13grs of HS-6. With the Iso Core alloy these actually drop at 260grs and with the 640 the small HP's drop at about 275grs and the large HP's around 265grs. My actual intent was to use the large HP's for my 45acp, but I haven't' gotten around to playing with it just yet.
So after running 5 rounds of each down range I headed down with my sifter to see how they had done. Granted the sandy loam I use in my buckets is no way close to critter matter, but it does give repeatable results which is about all I can hope for right now. I removed the screw on top and started to slowly shave off the layers of dirt until I reached the first indication of a boolit. With what little dampness there is in this dirt, usually there is a dry spot just before you reach the boolits. Very carefully I sifted the previous dirt I had removed looking intently for any sign of fractured or broken pieces of the expanded HP. None were found. So I continued to easily remove the dirt and found my first perfectly mushroomed HP. As I removed it I measured the depth at which it had stopped and found that to be 6". Just another inch or two over from that one was another and then another, all looking like I had put them through a press of sorts, to get them to look almost identical. Here are a coupe which represent for the most part every one I recovered to some extent.
These were from 25yds,
http://castboolits.gunloads.com/imagehosting/2895504c6af9e55ac.jpg
and these from 50yds,
http://castboolits.gunloads.com/imagehosting/2895504c6af9abfc0.jpg
After recovering the 5 640's I gently dug a bit deeper until the tell tale sign of another boolit appeared. Again I gently removed the dirt until the boolit fell from the sand. Again I held in my hand another perfectly formed mushroom. I dug a bit deeper and found the other 4 resting at a depth of 8".
To be honest I had figured they would have been a bit deeper than they were but I am not overly concerned as the dirt does do a good job of stopping things.
So after replacing and packing the sand back into the bucket I pulled it in closer to the 25yd mark. I wanted to see if they would hold up to a bit higher impact speed. Again I started with the 45 270 SAA as I knew it would be deeper and hopefully not booger up the others. I fired 5 for group this time. After those were done with I put up another target and loaded up 5 more of the 640's. Again I fired for group and after I was done headed out to sift them out. The accuracy was pretty darned close to what I have been getting with the other loads as well.
Once again I was VERY pleased to find not only were there 10 perfect mushrooms, but thee were no signs of any fracturing or cracking anywhere I could find on the recovered boolits.
So hopefully I will be able to find a hog in the near future to test them out on. I am not overly worried about the penetration as I know that they will neither expand nor stop as short when they hit flesh as they did in the soft sand. My purpose was to put together an alloy using the large Iso core which would readily expand and not fracture the noses off as it did so. This I have accomplished. At least with the 45 Colt. The others remain to be tested. I do have pictures, but it will be sometime tomorrow or Monday before I can get them up.
So anyway here is my formula if anyone else with some of the large Iso Cores wants to give it a try,
1.5 / 1.5 / 97
Pure Tin - .0995# or 1.6oz
Pure Lead - 4.9# or 78.4oz
Large Iso Core alloy - 5# or 80oz