For the casters out there. I got this information on an 8.6 forum. Pretty good information.
Cast bullets in the 8.6!?
In the name of science, I ordered in a 270gr NOE mold and alloyed up a 24 BHN test batch of lead. The bullets were cast, coated in zombie flavored HTC, and cured to perfection. After sizing to .339, I grabbed my keg of H110 powder and worked up a ladder from 8.5-16 grains in half grain intervals, then headed to the range with my chrony and the RPM Tester 3000 prototype.
I set out to learn three things:
1. Will HARD cast bullets hold up at subsonic velocities and the associated rpm from a 16" 3 twist barrel without leading?
2. If so, at what velocity/rpm will they fly apart?
3. Is it possible to produce a quality sub for less than .20/round?
By my calculations, a muzzle velocity of 1000 fps in a 3 twist barrel generates 240,000 rpm.
RPM = Muzzle Velocity * (720/twistrate)
Velocity data and notes as follows:
8.5 gr 792 fps
9 gr 845 fps
9.5 gr 882 fps
10 gr 930 fps
10.5 gr 992 fps
11 gr 1031 fps
11.5 gr 1070 fps
12 gr 1115 fps. *Bullets spun apart out of the muzzle*.
15 gr 1328 fps *frag out!* (see final RPM Tester 3000 pic)
None of the loads left any leading in the barrel which leads me to believe they were not stripping the rifling and had enough obturation to mitigate gas cutting.
Testing was done through a 16" faxon remage barrel. Bullets seated to 2.700"
The RPM Tester 3000 worked flawlessly, and yeilded photo evidence that my cast loads can handle up to 270,000 rpm! (I've never spun lead any faster than 160K rpm previously)
Moving forward, I plan to load (and accuracy test) at least 100 rounds in the 10.5-10.7 grain range to verify single impact holes on a paper target before attaching any muzzle device.
Final thoughts: the first two items I sought to learn were accomplished. #3 is pending accuracy testing, but it is looking promising! I have a feeling this bullet will be the bee's knees for .338 razorback nano sonic with a 1:6.5 twist too.
Cast bullets in the 8.6!?
In the name of science, I ordered in a 270gr NOE mold and alloyed up a 24 BHN test batch of lead. The bullets were cast, coated in zombie flavored HTC, and cured to perfection. After sizing to .339, I grabbed my keg of H110 powder and worked up a ladder from 8.5-16 grains in half grain intervals, then headed to the range with my chrony and the RPM Tester 3000 prototype.
I set out to learn three things:
1. Will HARD cast bullets hold up at subsonic velocities and the associated rpm from a 16" 3 twist barrel without leading?
2. If so, at what velocity/rpm will they fly apart?
3. Is it possible to produce a quality sub for less than .20/round?
By my calculations, a muzzle velocity of 1000 fps in a 3 twist barrel generates 240,000 rpm.
RPM = Muzzle Velocity * (720/twistrate)
Velocity data and notes as follows:
8.5 gr 792 fps
9 gr 845 fps
9.5 gr 882 fps
10 gr 930 fps
10.5 gr 992 fps
11 gr 1031 fps
11.5 gr 1070 fps
12 gr 1115 fps. *Bullets spun apart out of the muzzle*.
15 gr 1328 fps *frag out!* (see final RPM Tester 3000 pic)
None of the loads left any leading in the barrel which leads me to believe they were not stripping the rifling and had enough obturation to mitigate gas cutting.
Testing was done through a 16" faxon remage barrel. Bullets seated to 2.700"
The RPM Tester 3000 worked flawlessly, and yeilded photo evidence that my cast loads can handle up to 270,000 rpm! (I've never spun lead any faster than 160K rpm previously)
Moving forward, I plan to load (and accuracy test) at least 100 rounds in the 10.5-10.7 grain range to verify single impact holes on a paper target before attaching any muzzle device.
Final thoughts: the first two items I sought to learn were accomplished. #3 is pending accuracy testing, but it is looking promising! I have a feeling this bullet will be the bee's knees for .338 razorback nano sonic with a 1:6.5 twist too.
