Well we just changed to Gen 5 Glock 17s from Gen 4 Glock 22s and our LT in charge of special ops, ex FBI SWAT guy, most likely had a say in the ammo we got. 135 Hornady Critical Duty is what we use now and he bumped us up to 62 gr 223 from 55 gr. Before we used 180 gr Winchester Ranger in .40 cal.

When we switched from .40 to 9mm, it was 180 grain Federal HST to 147 grain Winchester Ranger. Between the contract being announced and getting the guns (Glock 47, 19 and 26… but we only get 19s), Speer won the ammo contract with the 147 grain G2. Supposedly it was “optimized” for the Glocks, but the only visible difference between the contract stuff is the box marked DHS and the bullet blackened. For the time that I’ve been shooting it, very happy with performance. I was at a class earlier this month where we had the chance to shoot thru a windshield… round hit 1.5 foot above POA at 7 yards (all rounds tested shot high), but zero issues shy of that.

I’ve always stuck with 147 grain. My 9mm converted S&W 642-1 runs 147 grain Hornady XTP… 115 grain UMC bulk had same POI (due to how weak it was) and I still have some for training. I’ve also got a decent amount of 147 grain Federal Syntech, which works great as a low lead option (polymer coated).

But unfortunately, I will likely have to source some 124 grain as H&K P7s run 100 thru 125 grain for reliability. Probably will do that Federal option where you get Syntech and HST packed together… and see how they run in the pistol.

147 HST JHP

This is my choice.

68gr.

I use it in all my 9's. Lehigh/Underwood Extreme Defense +P+ I think.

It has the interesting advantage of penetrating IIIa soft armor. Additionally, it has low recoil allowing fast flat shooting. It also makes for a lighter weight gun to carry.

Only one better is same bullet in .357sig, which I also have. That one screams somewhere over 2000fps I think.

I carry 124gr HST's in my G19

Well, yes and no. Sorta.
Bullets work on three ways;
They poke holes in the peoples doing damage along the way. Damage that makes certain things non-functional. Depending on which parts of the human structure are broken, a "peoples" can remain functional for a long enough time to be a threat, even when "shot".
Second, they make the blood leak out or, interfere with the body's ability to supply blood to the affected area. Such as the brain. Enough blood leaks out there's not enough oxygenated blood for brain function and the peoples passes out. Damage the lungs/heart, same effect. Blood loss takes a bit to take effect.
Then there's the Central Nervous System shot. Damage these structures and the non-functional effect can be quicker.

Shot placement is key.

Bigger hits harder. Just like cars. Same principle. Bigger holes, bigger damage. Caliber. Expanding bullets do present "bigger" when they expand, which they sometimes don't always. Primarily, an expanding bullet designed for defensive use is more for limiting penetration. (preventing over-penetration)
Please note. Torso shots don't always mean the bullet stays in. Even with hollow points. Arms, legs, not always. Not even head shots will always stay in. Depends.

ANY bullet can over penetrate its target. If you shoot, be sure of your target and what's around/behind it.

Faster also hits harder but comes at a risk of over penetrating. A big bullet going fast in theory, would "work better" than a small bullet going slower.
The world isn't perfect. Bullets don't always do what we think they should.
So. Use a load that functions 100 percent in your gun. One that's accurate. Place your shots properly. Use enough. What happens next isn't up to you.

My pick is still Gold Dot when I can get it. In 9mm I prefer their 124gr+p but I'll use the standard velocity load if that's what I can get. Federal and Hornady both make excellent carry loads. As does SuperVel. If you can find it. Supply & demand.

Over forty years I saw people get shot a lot but still keep going. Then the one 22 to the chest, drops somebody like they were poleaxed. Go figure. Head shots that weren't fatal or even "stoppers", 5.56 rifle rounds that didn't penetrate a solid torso hit and some that did. Same went for handgun bullets.

In range testing, 10 percent ballistic gelatin using the FBI protocols one can see the relationship between controlled expansion, penetration, bullet weight, velocity and retained weight. Even that didn't always predict what happens on the street. Imagine that.

Police generally anticipate a range of scenarios they must account for, using one bullet. So their pick has to do well over a broad range on performance standards. People. People with light and heavy clothing. Vehicles. The ability to penetrate common materials and still perform on the peoples. Drywall. Wood. Etc. Regular folks probably worry about performance on peoples primarily and not so much on vehicles and such. However. One never knows, especially these days. Getting kind of weird out there.