While 115 grain 9mm is probably the most common 9mm bullet weight, it seems that the Europeans like the 124 grain loads. Heck the NATO standard load is 124 grains and that originated in Europe.
Thoughts?
It may be true that 115gr is most common for commercially manufactured loads in the US, but that's a matter of money -- people buying their ammo neither care nor know the difference, and 115gr bullets are simply cheaper for the manufacturers to use, and thus they charge less. Even the modest uptick of price for 124gr at the counter at Walmart will be enough to turn most buyers to the 115gr at a dollar or two cheaper. And while we might appreciate the difference in recoil at the same power factor, most 115gr cheap ammo is loaded light, most buyers don't know there will be a difference, and if you don't know there is a difference, it's incredibly unlikely you would recognize one when the last time you shot a different weight was the last time you shot at all, which for most gun owners is 2-12 months earlier. That's why 115 is most common commercially. They are not most common for purpose-loaded cartridges by reloaders.
My most accurate loads with my CZ ShadowLine have been with the 115gr Hornady HAP. I haven't shot the 125gr HAP, so I suppose that might be even more accurate.
It is undoubtedly true that certain twist rates will work better with certain bullet weights.
It can also be true that certain bullet weights will perform best at certain velocity ranges in certain guns, also at least in part tied to twist rate.
I have done no serious load development at 50 yards for 9mm (.45, yes, but not 9mm). I've done a little 9mm development at that range, but not enough to speak with authority on what works best for my pistols.
But out to 35 yards, with the exception of that 115gr Hornady HAP, 124/125gr has performed best. I am in no way sure that this means 124/125gr is best in my pistol, in general. Rather, for the application I load for -- 9mm action pistol -- and the velocities I load to for that application, 124/125gr is best. The transonic range from around 1100 - 1150 (true transonic range is much larger, but 1100-1150 is the really bad range) will affect accuracy negatively, so I prefer to stay below or above that all the way to the target, which out to 35 yards means starting below 1100, or above maybe 1180/1190. For 50 yards, it means starting over 1200. For all I know, I might find more accurate loads over 1200 feet/sec, but THAT is not acceptable for my primary application in terms of recoil, so I am staying under 1100 by default. Given that ceiling, and given the desire to mitigate recoil, and given that my ShadowLine does best in terms of accuracy with 124/125gr bullets between 1060-1080, which falls right into that 132-134 power factor sweet spot for 9mm minor, 124/125gr is simply the best choice for me in my ShadowLine.
But is it most accurate in my pistol, best load at any weight? I don't know. I haven't done that testing. I will tell you that the majority of people who handload 9mm for 50 yard bullseye competitions load 115gr JHP to velocities over 1200 feet/sec, so if there were 124gr bullets that would do better, I don't think we'd see the precision guys shooting 115gr at such high percentages. Shooting sports are copy-cat sports, where people copy what the winners are doing, and the handloading winners are most often shooting 115gr IF they are shooting 9mm.
Most non-bullseye shooters don't do serious accuracy testing. Since so many people in forums are loading for action pistol 9mm minor, and since people in that group often perpetuate an idea that ultimate accuracy isn't that important, people just look for
good enough, and good enough ain't that great. People will test for accuracy at ten yards for a sport that shoots out to 35. People will make assumptions about the most accurate load at 10 yards being the most accurate load period, but that is far from true. I have tested loads against one another where the load that performed best at 15 yards was not best at 25, and conducted the test more than once on different days to show it was repeatable for the loads at hand. Bullets don't just launch from the muzzle in a slightly variable direction and travel straight to the target like a laser. They wobble and dance and drift further off the straight and narrow with each passing moment like a bridesmaid with access to an open bar. The longer it takes for the bullet to get home, the more the variables that affect accuracy are magnified, and sometimes the dominant variable at 10 or 15 yards is not the dominant variable by the time you get to 25 or 35.
We all watch patterns emerge over time. Our brains are geared for pattern recognition. Sometimes the variable we attribute a pattern to is incorrect, however, and I suspect often what bullets we deem most accurate is a result of the appropriate velocities for the application we are loading for, and not necessarily universally applicable across all velocities.
Does my positive experience with 124/125gr in the narrow range I load for mean that 124/125gr is best overall? I have my doubts.
Food for thought. I am working again on a Sunday, so I will leave it at that.
