I was looking at someone who ported/drilled the pistol barrel and then opened up the top of his slide to release the gasses. Firing shows almost no recoil. I believe it is a 4.5" barrel, 9mm. Thinking this was interesting versus getting a threaded barrel and getting a brake, or suppressor. I looked online and there are a couple videos of folks testing the non-ported vs the ported. Huge recoil reduction but… They also showed there is almost no difference in bullet speed. How does this work? We have a general rule of thumb in rifles that 1" = about 15-25 FPS difference. If you port 2 inches of barrel, wouldn’t that make a difference in the bullet speed? Is it because all the length of a pistol barrel is for getting it to spin cleaner and fly truer? The speed of the bullet happens in teh first couple of inches?