I’m thinking about SBR’ing one of these for home defense use. Is there any significant velocity increase in an 8” barrel over the 4.5” (in 9mm?) The 4.5” would be handier, especially with a can on it. Seems like there was a website somewhere with various calibers and barrel length/ velocity, etc. ?

Thanks!

Google “Ballistics by the inch”.
I was kind of surprised at the velocity difference between a 16” and 10” gun.

Thank you, sir. That’s the site!

when adding a suppressor, the 4" barrel is better. especially with a short suppressor like the Omega 9K to keep the OAL short.

but I know that essentially, I am only going to get the same bullet effectiveness of my G19 - same bullet, same barrel length- but with much greater accuracy coming from a shouldered sub-gun.

According to the ballistics by the inch site, I’d gain approximately 100 FPS in the 8” over the 4.5. Not to terribly significant

Is one-fifth greater energy significant?

As an example using the standard pressure 124 grain Gold Dot load from a 4.4" barrel, the muzzle energy is 340 ft-lb. Increasing the velocity by 100 fps raises the ME to 404 ft-1b, a 19% increase. Energy is what enables projectiles to do damage to their targets: more energy = more damage.

Of course, there are those who claim to believe that energy differences in handgun projectiles make no difference to wounding effects. For them manufacturers should produce weapons chambered for less powerful and intimidating cartridges such as the 32 S&W or even 25 ACP; if produced in quantity, such rounds would be less expensive and easier to shoot.