I'm looking for a chance to try these on them next time. 55g RN .224 bullet, nose flattened with a small hollow point (using a small centre drill in the lathe), travelling at 1020 fps. Quieter than my 900 fps springer air rifle in a side by side comparison (son was shooting the air rifle), with the DPT suppressor on the rifle. Though now tempted to make some faster ones too, but pretty sure wouldn't want to exceed maybe 1800 fps.
Bullets are H&N 55gr RN, copper then polymer coated. The primer is the most expensive part of the cartridge, works out about 40c per shot.
Attachment 266944