Blue68f100
Member
Earlier this week I had neighbors over shooting at my range. All was going well till my neighbor chamber some 223R, 68-69gr BTHP Match loads. I had my crony setup but was not sending data to my phone app. Any way the first shot registered 3740 fps out of a 16" NATO chamber 1:9 twist. I told him to stop and lets see whats up. He fired again still in the 3700 fps range. I told him we need to break those down to confirm the load. He wanted to keep shooting so my neighbor and I backed way off. He shot a total of 5, that were off the charts. The other 5 shot loaded at the same time landed in the 2650 fps which is normal.
He came over this morning and I quizzed him on his loads. What I found out was he substituted Hornady 68gr in place of Sierra. He did not think 0.1 gr lighter would make any difference. He was using 24.5 or 25.4 gr (not sure which one) of CFE-223, 2.250" OAL, CCI 41 primer. The brass was A-USA or PPU. Once I found that out I showed him the 2 bullets side by side. For those who are not familiar with these, the Hornady 68 gr bullet is 0.090" longer than the Sierra 69gr HPBT. Hornady recommends a AOL of 2.250" while Sierra recommends 2.260". My data books does not show CFE-223 powder, but Hodgdon's show it for the Sierra 69gr, 23.5-25.8gr. I normally use Varget with these bullets and the max is 1.2gr higher with Sierra's 69gr max at 26.1gr.
So it appears he just swapped bullets, Hornady for Sierra.
This is a good example why you MUST compare bullet profiles before substituting data.
Can some one please plug these number into Quickload to see how close it was to blowing his gun up.
Be Safe.
He came over this morning and I quizzed him on his loads. What I found out was he substituted Hornady 68gr in place of Sierra. He did not think 0.1 gr lighter would make any difference. He was using 24.5 or 25.4 gr (not sure which one) of CFE-223, 2.250" OAL, CCI 41 primer. The brass was A-USA or PPU. Once I found that out I showed him the 2 bullets side by side. For those who are not familiar with these, the Hornady 68 gr bullet is 0.090" longer than the Sierra 69gr HPBT. Hornady recommends a AOL of 2.250" while Sierra recommends 2.260". My data books does not show CFE-223 powder, but Hodgdon's show it for the Sierra 69gr, 23.5-25.8gr. I normally use Varget with these bullets and the max is 1.2gr higher with Sierra's 69gr max at 26.1gr.
So it appears he just swapped bullets, Hornady for Sierra.
This is a good example why you MUST compare bullet profiles before substituting data.
Can some one please plug these number into Quickload to see how close it was to blowing his gun up.
Be Safe.