As promised, here are the results of testing the 280 HAT bullet against the 300 grain SMK.
I was in a race to find enough paper to shoot into and barely made it to the range tonight with enough time to make the chronos work before the sun set. Because of limited time and the fact that I didn't want to make a mess in the bed of my truck, I didn't soak the paper. It was packed tight and bone dry.
First step was to set up the two chronos back to back and fire the test ammo across them while getting a new zero for the seriously reduced velocity I was going to get. The MV of the 280 HAT's was registering at around 1989 fps on the Oehler 35 and around 1996 on my POS SHooters Chrony which came from a mild load of 48.0 grains of N170. The 300 SMK was loaded with 50.0 grains of N170 and registered at 1983 on the Oehler and 1989 on the Shooter's Chrony. The impact was WAAAYY low of what it usually is for the 300 SMK at 100 yards. But I quickly dialed up the needed amount and moved the SHooter's Chrony out to the 100 yard marker in front of the target.
Here's the pic:
I fired 5 HAT bullets of which one didn't register through the Shooters Chrony at 100 yards. But the other four were perfect reads. The Oehler MV was 2050,2029,1978,(1934 error on SC),1957 and the velos at 100 yards were 1948, 1940, 1888, 1867. You can do the exact math but the average velo loss was around 90 fps.
The 300 SMK velos were 1982, 1968 on the Oehler and 1904 and 1889 on the 100 yard SC. This was about a 78 fps loss.
Do the math and you get a bc of .684 for my environment parameters for the 280 HAT bullet and .797 for the 300 SMK. This is not far off what I got the last time I tested the bc of the 300 smk at .810. My barrel has had a few shots through it since then and the throat has become just a touch rougher.
So why didn't the HAT have a higher bc? The holes in the paper were point on but there possibly wasn't enough rpms to get this bullet totally stabilized at 100 yards. Or perhaps a longer range test would be more accurate. But I can't go any farther with my little chrono. The window is just too small. So perhaps someone can drop test the bc at normal MV speeds?
So, on to the media test. I fired three SMK's and three 280 HATs into the phone books at 100 yards with reduced velocities to simulate long range impact speeds. Since I already know what the 300 smk's do to animals at 1000 yards, I used it as the control. In this manner, I can make a comparison of the two bullets and I know what the minimum performance level is that can be accepted.
Well, the 300 SMK's left the muzzle at 1939, 1945,and 1910. The HAT's MV was 1913, 1900,and 1888.
When I opened the box, I was surprised to see this HAT bullet only 7 inches into the paper:
Then I kept digging and found another one just a bit farther in. Maybe 9 inches but I didn't actually measure it.
Then I noticed a hole in the dirt beside the box. It was a Hat bullet impact that had hit the box of paper low and turned down and zipped out the bottom of the box about 5 inches into the paper.