I was at the range with my son yesterday. I had loaded up a bunch of .40 for his XDSC. I gave him two batches of 50 rounds. They were both 175 gr SWC, 1.124 OAL, crimped to .422. The only difference was that one was loaded with 5.3 gr of Unique and the other was 5.6 gr of Unique. The 5.6 gr rounds shot wonderfully. The 5.3 gr rounds were all hitting about four inches low. He would switch between the batches from mag to mag and the 5.3 gr rounds were consistently about four inches low. Granted, this wasn't from a rest, but the rounds were punching perfect little groups about four inches below the POA.
I still have some headroom in the data to take the powder charge even higher than the 5.6 rounds, so I will keep working up. I was starting at the start data point in the data I have and working up.
I asked this on another forum and have largely gotten advice to just shoot the better load. Well, I'm certainly not planning on loading the same as the ones I have had problems with, but I am hoping that someone can point me in the right direction as to why we are seeing this.
I am totally perplexed! Any suggestions from the experts (or even the not-so-experts)???
Thanks,
Scott
I still have some headroom in the data to take the powder charge even higher than the 5.6 rounds, so I will keep working up. I was starting at the start data point in the data I have and working up.
I asked this on another forum and have largely gotten advice to just shoot the better load. Well, I'm certainly not planning on loading the same as the ones I have had problems with, but I am hoping that someone can point me in the right direction as to why we are seeing this.
I am totally perplexed! Any suggestions from the experts (or even the not-so-experts)???
Thanks,
Scott