G'day John and everyone,
It is my understanding that the old Speer Grandslam bullet had two lead cores of differing hardness but this has since been changed to the one lead core. Have I got this right? The old Speer manuals used to list separate data for Grandslam bullets as they mentioned pressures were different than other bullets of the same weight. Speer now list all bullets of the same weight, including Grandslams, together. I assume, correctly or incorrectly, that this means the Grandslam now exhibits similar pressure to other Speer bullets.
Is the 'new' Grandslam still a tough premium bullet or is it now similar to a Speer Hotcor cup and core. I recently purchased second-hand five boxes of 6.5mm 140gn Grandslams and was wondering if they are the old style or the new? Is there any way to tell the difference between the old style and the new? They are in the 50 count clear orange plastic boxes with the bullets vertical in their own little space the same as some 7mm Grandslams I bought 18 years ago. Or did the new style GSs come in the same boxes? I will load them in a 22" 6.5x55 so I would assume that even if they are the 'new' single core bullet they will still be adequate for fallow deer size game.
Sorry for rambling but the Grandslam is a bullet that never seems to get mentioned or written about anymore.
The 6.5 mm 140 was one of my favourites before they discontinued it quite a few years ago so the ones you have would be old bullets. The 6.5 mm looked to me like they were only one piece when I sectioned them the same as the 6 mm and 257 versions. Oddly enough I saw a press release that they are going to be offering 6 mm, 257 and 6.5 mm G.S. bullets for 2018, unsure what exact weights they will be though.
https://www.ammoland.com/2018/01/391921/#axzz57JkjJsHaI only have a few 6.5 mm 140's left and would love it if they brought that weight back. We shot quite a few deer and black bears with them from both the 260 and 6.5x55 and never had any problems at all. Complete penetration on every animal and there were quite a few.
