TurnipEaterDown
12-22-2021, 03:16 PM
So, some few years back I decided to design a cast bullet for my 44 Rem Mag.
I already had some successful work designing a couple wildcat rifle cartridges behind me, so thought 'why not' given that I had had disappointment up until that time w/cast bullets I had used in my mildly customized Ruger SBH. I knew cast bullets and revolvers should shoot well, I am not a heretic, and I had very good results w/ my Linebaugh 475, so I wanted to give it a go.
I did this because (1) commercial bullets I had tried in my 44 SBH generally didn't give me the accuracy I desired, leaded my barrel, and didn't save me $ while shooting, (2) the Lee 310 just didn't perform on game for me (if you had other luck, great, but for me I was disappointed after shooting a porcupine 4 times and several deer several times each), (3) the Lyman 429244 GC mold I used to have produced bullets that didn't satisfy me (again, great if they do for you, I never got good groups), (4) the LBT 260 WFN GC, while fantastic for me at 25-50 yd, does seem to have stability issues at 100 yd and beyond as some prominent gun writers report (groups Do open up for me).
What was I looking for?
Design criteria were: a bullet weight between 240 & 300 grains (to retain velocity above the speed of sound at impact), Plain Base (save me $ on GCs, time in finishing bullet, and to reduce a variable in bullet consistency - GC don't always fit perfect), easy to load (tolerant of small variation in length of case), easy to get to shoot well (i.e. not terribly finicky of powder or charge), stable at longer ranges, would fit in multiple firearms, and must have pronounced impact characteristics.
I did do a lot of bench-marking of successful designs in making the bullet design I did, so won't claim mystic abilities in the effort, but I did achieve what I wanted and so have decided to share the fruit of my effort.
If a reader doesn't like the design, or disagrees with something I present, so be it. It is what I found through my efforts and have very fine success in using. I have shot thousands of these, and at this point don't see anything I want to change.
They shoot better for me than the 429244, produce smaller groups at 100 & 200yds than the LBT 260 WFN GC, and create a better impact characteristic than other comparable bullets I have tested, including the Lee 310.
As a pleasant aside, the design allows high powder charges to be used at very reasonable pressures.
Detail of my bullet design is below, with abbreviated test results:
Measurements listed represent caliper measurements of as cast bullet from original Mountain Mold provided to my design.
This bullet is now offered by Accurate Molds as 43-280G. Dimensions there were derived from my measurements below sent to the owner or Accurate Molds, and likely from as cast samples I also provided.
0.31" Long Nose
0.34" Meplat (Nose flatness important for cavitation in wound channel)
0.1" Driving band (outside of case)
0.055" wide crimp groove 0.020" deep
0.100" first body band
0.100" grease groove, 0.021" deep
0.110" base band (I wanted a "chunky" band to provide good support under moderately high pressure)
0.772" total overall length
0.41" outside of loaded case
1.685" loaded COL w/ 44 mag case trimmed @ 1.275"
Design Notes: Generous crimp groove is tolerant to trim length. Nose designed to try to match rifling engagement taper to common forcing cone angle
Pressure data:
280 gr Mountain, ~1.69"
WW296 with fed 155, 14" TC bbl (included 1 5/8" brake)
24 gr 1481 fps @ 26,000 psi
293467
Photos below show unsized and unfired 280 Mountain Mold cast bullet designed by me.
293468
In photos below the Left (actually Upper, photo is rotated) water saturated phone book was hit twice w/ 280 Mountain, once (Left Top of this photo, on the top right in original) with a soft nose of ~ 90 grains loaded to 1440 fps with 25 grains W296 and a WLP primer, same load without soft nose on Left Bottom (left top on original photo). Distance ~ 15 yards. This load makes probably ~ 30,000 psi. Note that Hard cast produced greater surface opening in the saturated newsprint.
Hardcast bullet was 23-27 BHN (as was base of softnose bullet). Alloy either quenched wheel weight w/ antimony added or quenched “HP Alloy” that I use (made of 5 lbs indoor rimfire/airgun range lead, ½ - ¾ lb 60/40 Antimony/tin, and 1 lb high arsenic shot). Penetration distance was measured ~ 12”
Right phone book (Bottom in original photo) was hit once w/ 310 LEE (with a soft nose of 90 grains) loaded over 21.5 grains A300MP and a WLP primer. ~ 1250 fps. Distance ~ 15 yards. Penetration distance was measured ~ 13”
For both 44 bullets, a Ruger SBH 44 Magnum test arm with 7.5” barrel was used. Pictures are from September 2016.
293470
3 Recovered Bullets in this photo below (First 3, in order Bottom to Top of included photo, in original photo, L to R) were in the hard cast 280 Mountain, Softnosed 280 Mountain, and softnosed 310 LEE all after being fired into the phone books.
Note the riveted nose on the hardcast 280 mountain as recovered. The Nose is of Bigger diameter after recovery than the Body at loading.
This hard bullet did Not “shatter” as some will suggest that they will. Perhaps this is because these were shot into wet newsprint (decent simulation of muscle tissue) and no hard object was struck. However, I will say that I have shot a lot of hard bullets into rock filled clay banks and none that I ever dug out were found shattered, they often had portions sheared away, but I always saw Plastic Deformation, Never shattering. Retained weight of the hardcast 280 after recovery was basically same as unfired. All recorded BHN prior to firing that are noted were measured with LBT hardness tester. Some loss of hardness has occurred w/ time w/ these alloys. What they were at firing may have been slightly less.
293471
As a comparison, a caliber & bullet weight often noted for good penetration was also fired into this test media on the same day / time.
The 3 topmost Bullets in this same photo above (1/2 way up, to top in the photo, or midpoint to right in original photo presentation) were the hard cast 370 RCBS fired from Steyr 41 40 into the phone books, and two (2) Softnosed 370 RCBS fired into the phone books. Velocity at muzzle of the 41 40 rounds was 1650 fps. BHN of base/whole non-softnosed 416 bullet was 20-24 (quenched WW).
Note that the softnosed bullets were all found with the soft lead having sheared away down to the hardcast base material (both 44 & 416 calibers).
293472
The impact characteristic of these three 416 bullets are seen in photo above. In bottom of the photo (Left in original photo) from the hardnose variant and 2 upper bullets (far right most in original photo) of softnose variant. Looking at notes from the time, penetration was ~ 17”. Note that the impact characteristic of the 416 bullets (having a SWC "Keith" nose), were less profound than the 44 280, though driven 200 fps faster and impacting at the same distance from the muzzle.
The little hole in the middle of these was a 30-06 165 SST loaded to full velocity.
I already had some successful work designing a couple wildcat rifle cartridges behind me, so thought 'why not' given that I had had disappointment up until that time w/cast bullets I had used in my mildly customized Ruger SBH. I knew cast bullets and revolvers should shoot well, I am not a heretic, and I had very good results w/ my Linebaugh 475, so I wanted to give it a go.
I did this because (1) commercial bullets I had tried in my 44 SBH generally didn't give me the accuracy I desired, leaded my barrel, and didn't save me $ while shooting, (2) the Lee 310 just didn't perform on game for me (if you had other luck, great, but for me I was disappointed after shooting a porcupine 4 times and several deer several times each), (3) the Lyman 429244 GC mold I used to have produced bullets that didn't satisfy me (again, great if they do for you, I never got good groups), (4) the LBT 260 WFN GC, while fantastic for me at 25-50 yd, does seem to have stability issues at 100 yd and beyond as some prominent gun writers report (groups Do open up for me).
What was I looking for?
Design criteria were: a bullet weight between 240 & 300 grains (to retain velocity above the speed of sound at impact), Plain Base (save me $ on GCs, time in finishing bullet, and to reduce a variable in bullet consistency - GC don't always fit perfect), easy to load (tolerant of small variation in length of case), easy to get to shoot well (i.e. not terribly finicky of powder or charge), stable at longer ranges, would fit in multiple firearms, and must have pronounced impact characteristics.
I did do a lot of bench-marking of successful designs in making the bullet design I did, so won't claim mystic abilities in the effort, but I did achieve what I wanted and so have decided to share the fruit of my effort.
If a reader doesn't like the design, or disagrees with something I present, so be it. It is what I found through my efforts and have very fine success in using. I have shot thousands of these, and at this point don't see anything I want to change.
They shoot better for me than the 429244, produce smaller groups at 100 & 200yds than the LBT 260 WFN GC, and create a better impact characteristic than other comparable bullets I have tested, including the Lee 310.
As a pleasant aside, the design allows high powder charges to be used at very reasonable pressures.
Detail of my bullet design is below, with abbreviated test results:
Measurements listed represent caliper measurements of as cast bullet from original Mountain Mold provided to my design.
This bullet is now offered by Accurate Molds as 43-280G. Dimensions there were derived from my measurements below sent to the owner or Accurate Molds, and likely from as cast samples I also provided.
0.31" Long Nose
0.34" Meplat (Nose flatness important for cavitation in wound channel)
0.1" Driving band (outside of case)
0.055" wide crimp groove 0.020" deep
0.100" first body band
0.100" grease groove, 0.021" deep
0.110" base band (I wanted a "chunky" band to provide good support under moderately high pressure)
0.772" total overall length
0.41" outside of loaded case
1.685" loaded COL w/ 44 mag case trimmed @ 1.275"
Design Notes: Generous crimp groove is tolerant to trim length. Nose designed to try to match rifling engagement taper to common forcing cone angle
Pressure data:
280 gr Mountain, ~1.69"
WW296 with fed 155, 14" TC bbl (included 1 5/8" brake)
24 gr 1481 fps @ 26,000 psi
293467
Photos below show unsized and unfired 280 Mountain Mold cast bullet designed by me.
293468
In photos below the Left (actually Upper, photo is rotated) water saturated phone book was hit twice w/ 280 Mountain, once (Left Top of this photo, on the top right in original) with a soft nose of ~ 90 grains loaded to 1440 fps with 25 grains W296 and a WLP primer, same load without soft nose on Left Bottom (left top on original photo). Distance ~ 15 yards. This load makes probably ~ 30,000 psi. Note that Hard cast produced greater surface opening in the saturated newsprint.
Hardcast bullet was 23-27 BHN (as was base of softnose bullet). Alloy either quenched wheel weight w/ antimony added or quenched “HP Alloy” that I use (made of 5 lbs indoor rimfire/airgun range lead, ½ - ¾ lb 60/40 Antimony/tin, and 1 lb high arsenic shot). Penetration distance was measured ~ 12”
Right phone book (Bottom in original photo) was hit once w/ 310 LEE (with a soft nose of 90 grains) loaded over 21.5 grains A300MP and a WLP primer. ~ 1250 fps. Distance ~ 15 yards. Penetration distance was measured ~ 13”
For both 44 bullets, a Ruger SBH 44 Magnum test arm with 7.5” barrel was used. Pictures are from September 2016.
293470
3 Recovered Bullets in this photo below (First 3, in order Bottom to Top of included photo, in original photo, L to R) were in the hard cast 280 Mountain, Softnosed 280 Mountain, and softnosed 310 LEE all after being fired into the phone books.
Note the riveted nose on the hardcast 280 mountain as recovered. The Nose is of Bigger diameter after recovery than the Body at loading.
This hard bullet did Not “shatter” as some will suggest that they will. Perhaps this is because these were shot into wet newsprint (decent simulation of muscle tissue) and no hard object was struck. However, I will say that I have shot a lot of hard bullets into rock filled clay banks and none that I ever dug out were found shattered, they often had portions sheared away, but I always saw Plastic Deformation, Never shattering. Retained weight of the hardcast 280 after recovery was basically same as unfired. All recorded BHN prior to firing that are noted were measured with LBT hardness tester. Some loss of hardness has occurred w/ time w/ these alloys. What they were at firing may have been slightly less.
293471
As a comparison, a caliber & bullet weight often noted for good penetration was also fired into this test media on the same day / time.
The 3 topmost Bullets in this same photo above (1/2 way up, to top in the photo, or midpoint to right in original photo presentation) were the hard cast 370 RCBS fired from Steyr 41 40 into the phone books, and two (2) Softnosed 370 RCBS fired into the phone books. Velocity at muzzle of the 41 40 rounds was 1650 fps. BHN of base/whole non-softnosed 416 bullet was 20-24 (quenched WW).
Note that the softnosed bullets were all found with the soft lead having sheared away down to the hardcast base material (both 44 & 416 calibers).
293472
The impact characteristic of these three 416 bullets are seen in photo above. In bottom of the photo (Left in original photo) from the hardnose variant and 2 upper bullets (far right most in original photo) of softnose variant. Looking at notes from the time, penetration was ~ 17”. Note that the impact characteristic of the 416 bullets (having a SWC "Keith" nose), were less profound than the 44 280, though driven 200 fps faster and impacting at the same distance from the muzzle.
The little hole in the middle of these was a 30-06 165 SST loaded to full velocity.