The Firing Line Forums - View Single Post - IMR-4227 in 357 mag

buck460XVR · January 25, 2015, 02:29 PM

Which 158 gr JHP? Lyman shows a max of 16.1 under a Hornady JHP. I would think you would be safe at least working up to that if done properly. FYI, Speer shows a max of 17 under all of it's 158 grainers. It's starting load is 15gr. In most of my applications with IMR4227 the best performance comes just at or slightly above compressed. IMR4227 is notorious for leaving "kernels" especially at the lower end of it's parameters. While I only use IMR4227 occasionally for .357, I use it often in .44 mag and it is my go to powder in .460. While it does not give me the velocities of H110/W296 in those calibers, it does give me excellent accuracy in all of them. Velocities are similar to 2400.

January 25, 2015, 02:29 PM	#3
buck460XVR Senior Member Join Date: December 28, 2006 Posts: 4,342	Which 158 gr JHP? Lyman shows a max of 16.1 under a Hornady JHP. I would think you would be safe at least working up to that if done properly. FYI, Speer shows a max of 17 under all of it's 158 grainers. It's starting load is 15gr. In most of my applications with IMR4227 the best performance comes just at or slightly above compressed. IMR4227 is notorious for leaving "kernels" especially at the lower end of it's parameters. While I only use IMR4227 occasionally for .357, I use it often in .44 mag and it is my go to powder in .460. While it does not give me the velocities of H110/W296 in those calibers, it does give me excellent accuracy in all of them. Velocities are similar to 2400.