Open Guns. 9mm or 38 Supercomp?

pros and cons of 38 supercomp vs 9mm major when building a open gun for competition.

I’ve been asked what caliber Open gun would be best for USPSA/IPSC competition a lot this past month. It’s something I’ve had to research a great deal lately because of the Open build Mclearn Custom did for me last month. Caliber is the number one question when building a major open gun and deserves careful consideration.

The two main options nowadays are either 9mm major or 38 supercomp. Both have pros and cons and both are good options. I want back and forth for a long time deciding


                                                                     PROS & CONS


  • 38 Supercomp Pros:
  1. Softer shooting
  2. 10 plus reloads per case
  3. More consistent ejection
  4. Many powder options
  5. Able to use standard upright C-more with large viewing area.
  • 38 Supercomp Cons:
  1. Expensive initial investment “Starline Brass”
  2. Losing brass at major matches that are lost brass matches
  3. Having to pickup brass all the time

  • 9mm Major Pros:
  1. Little to no initial investment
  2. Don’t worry about retrieving all your brass
  3. Major matches don’t cost any extra because of lost brass
  • 9mm Major Cons:
  1. Erratic ejection because of mixed headstamps
  2. Unreliable with upright mounted C-mores “because of #1”
  3. Snappy compared to Supercomp
  4. limited powder choices when making major
  5. short brass life “2-3 reloads max”
  6. Need to use micro dot sight or side mounted C-more


I originally wanted to run 9mm and not change my reloading setup or worry about picking up brass like a crazy person. It was a struggle, on the one hand 9mm brass is cheap and easy but I really wanted to run a standard C-more mounted upright, any chance of a malfunction is not an option at nationals level matches. I had to take a deep look at what my goal for the pistol would be. Winning was that goal and after going round and round I finally decided that the extra initial cost of 38 Supercomp would put me in a better position to perform at my best.


Here’s a picture of the completed open gun by Mclearn Custom