I’m a beginner in USPSA Production (3 months into it) and have been seeking ways to achieve more competitive performance from my tools. Felt recoil seems to be the greatest obstacle to split times. Muzzle energy created by the acceleration of the bullet is the positive contributor to felt recoil. There are lots of negative (reducing) contributors: gun weight, recoil spring, gas venting, etc. There is a great thread on modifications for some of those negative contributors here:
I decided to take a closer look at muzzle energy (foot pounds of force or Joules) with the hopes to finding a cartridge that has the lowest positive contribution to felt recoil. I only shoot manufacturer ammo (for now) and compared LAX and Freedom Munitions for their various new 9mm cartridges. NOTE --- This comparison is for muzzle velocity only, it does not consider reliability, accuracy, or the conversion to felt recoil for your specific firearm. Also, I’m not a physicist, so hopefully I’m using correct vernacular.
SEE ATTACHED SPREADSHEET
The lowest muzzle velocity cartridges are the 147 grain options from Freedom at only 264 ft.lbs of force.
The 135 grain options from both LAX and Freedom are the next lowest at 288 ft.lbs(f). This is 9% more energy than the lowest option.
I’ve been shooting the 115 RN from LAX. It has the lowest power factor, right at the minimum 125 for Production, but is firing with 14% more energy (302 ft.lbs(f)) than the lowest option. Turns out Power Factor and Recoil are only casually related… acquaintances, really.
On the spreadsheet, I’ve listed some “Considerations”. Here is their meaning:
Weight Soft(er) = Heavier bullets accelerate more slowly through the barrel. It’s milliseconds, but may be enough to slightly dampen felt recoil even further.
Velocity Snappy = Lighter bullets accelerate more quickly through the barrel. It’s milliseconds, but may be enough to slightly strengthen felt recoil.
NATO Accuracy = The twist rate of many 9mm barrels are designed for a 124 grain projectile.
I have some current prices listed, too. This is certainly a strong consideration.
I hope some folks find this helpful! I’d be interested in receiving some feedback to my analysis. Is it relevant, sound, and have your experiences matched this theory? My next step is to put these calculations into practice. I’m going to buy a variety of these cartridges and run them through my Glock 17 over the next several weeks. I’ll update this thread with pictures and findings.
Recoil Analysis - 9mm - LAX vs Freedom.xls