Best Bullet Weight for 9mm with 3.6in Barrel?

[CEW58]

In this thread I’ve been discussing buying a 9mm for my girlfriend, most likely either a Sig P239 or a Glock 26. Both have a 3.6 inch barrel. My experience with the 9mm is limited to the M9 (Beretta 92) using military FMJ ammo. (I carry either a .40 S&W or a .357 Mag)

So assuming we buy either firearm with a 3.6 inch barrel, which bullet weight will perform best for self-defense?

[DefensiveCarry.com]

[MattInFla]

Speer makes a +p Gold Dot load especially for short barrels. That's what I carry in my M&P 9c.

[CEW58]

Speer makes a +p Gold Dot load especially for short barrels. That's what I carry in my M&P 9c.

I just looked that up on their website:

Gold Dot Short Barrel Personal Protection - 9mm Luger +P
124 gr with a muzzle velocity of 1150 fps out of a 3.5 in test barrel

Sounds good!

Have you had any issues with your M&P9c? I keep reading about "inadvertent magazine drops" and a few other issues. That's the reason I didn't include it in my list of compact 9mms.

[MattInFla]

There were some issues with soft magazine releases being rounded off though use. I had one of those, and S&W sent me two replacement parts express mail.

Replaced the magazine catch with the new one, and it's never been a problem since.

With the exception of the mag release issue, it's been a very reliable pistol. Never had a failure to feed or extract with it, and it's had at least 1,500 rounds through it.

Matt

[Brady]

I always try to go with the heaviest bullet I can find. Look hard for some 147 grains and try them out at the range. Do the wet phone book test and compare with other rounds.

[Archie]

There are two ways to get 'power' from a projectile. One is to measure by kinetic energy, which is equal to one-half of the product of multiplying the mass of the bullet by the velocity squared. (This is foot pounds of energy.) The other method is momentum. This is simply mass times velocity and it isn't normally discussed much.

'Energy' is more dependent on velocity, 'momentum' is more dependent on bullet weight.

I'm a heavy bullet guy from the start. In short barrels, where velocity can suffer by comparison, bullet weight tends to maintain momentum. So I'm still a heavy bullet guy.

By the way, there is no measurable answer as to which works better. (Which explains the never ending "9 vs 45" argument.) You're a big kid and it's your gun; take your pick.