gamestalker
member
I've noticed that Sierra 110 gr. .357 bullets are very different than other common jacketed bullets. I've only had Hornady, Winchester, and Speer to compare them to, but I would immagine others share simular bearing surface characteristics. Specifically, I'm referring to the area of the bullet above the canelure. On other bullets I've loaded the surface area above the canelure is the same diameter as the area below the canelure, which in this instance is .357" But Sierra's 110 gr. HP's only have a .357" bearing surface below the canelure for some reason. This especially causes problems because I load with H110/296 so I wind up with too much bullet jump to the cylinder bearing surface and forcing cone. This effects accuracy, but more importantly allows high pressures to get in front of the bullet, disrupting the bullet during it's travel to the barrel therefore causing it to misallign with the forcing cone because it has become cantered. This design also allows full developing pressures to blow back into other cylinders before the bullet ever leaves the cylinder. It's so noticable, that the recoil surface of the frame has permanent pressure imprints of the top two cartridge heads. And talk about issues with trying to get a crimp to keep the bullets from jumping out of the mouth. No way you can crimp deep enough to hold the bullet in place because there is only one side to the canelure, the bottom half.
I realize it isn't really practicle to load with H110 or 296 for a 110 gr. bullet, but it is a listed load and therefore should be capable of being safely accomplished. I don't experience these problems with Hornady, Winchester or Speer. Nearly every one I've loaded jumped the crimp, despite the fact that my crimps were tight as cold be without collapsing the wall of the brass.
I confired with a couple of experts, one was a Sierra guy, he didn't make any excusses and was actually very focussed on explaining this with a sincere approach. He stated that in general, smaller bullets in the .357 mag are often responsible for damaged forcing cones when loaded with large quantities of slow burning powders because they are still peaking before the bullet ever leaves the barrel. S&W also did some testing with smaller lighter bullets being loaded with large quantities of slow burning powders. Nothing conclusive was determined though, but the testing was performed with a 125 gr. bullet, not the 110s which are likely more problematic being they have a much shorter bearing surface which creates more free bore and bullet jump.
Anyway, I was just curious if anyone else has noticed the extreme difference or had problems because of this excessive free bore difference between the Sierra and other common bullet brands of 110 gr. weight.
I realize it isn't really practicle to load with H110 or 296 for a 110 gr. bullet, but it is a listed load and therefore should be capable of being safely accomplished. I don't experience these problems with Hornady, Winchester or Speer. Nearly every one I've loaded jumped the crimp, despite the fact that my crimps were tight as cold be without collapsing the wall of the brass.
I confired with a couple of experts, one was a Sierra guy, he didn't make any excusses and was actually very focussed on explaining this with a sincere approach. He stated that in general, smaller bullets in the .357 mag are often responsible for damaged forcing cones when loaded with large quantities of slow burning powders because they are still peaking before the bullet ever leaves the barrel. S&W also did some testing with smaller lighter bullets being loaded with large quantities of slow burning powders. Nothing conclusive was determined though, but the testing was performed with a 125 gr. bullet, not the 110s which are likely more problematic being they have a much shorter bearing surface which creates more free bore and bullet jump.
Anyway, I was just curious if anyone else has noticed the extreme difference or had problems because of this excessive free bore difference between the Sierra and other common bullet brands of 110 gr. weight.
