# Which bullet weight



## Murtaugh (Feb 15, 2016)

Hi All:

I just got a Glock 19 that I'll be reloading for. In the past I've reloaded for .38 spl.
As most of you know, the bullet weight ranges for the 9mm are basically: 115, 124 and 147. 
There are the two camps about bullet weights; those that think the heavier but slower bullet is more effective than the lighter and faster bullets.
I used to be in the heavier is better camp but am starting to change my mind.
In other words, why use 147 bullets over 124s... or 115s for that matter?


----------



## Bisley (Aug 24, 2008)

The short answer (for me) is POI vs. POA.

My 9mm's range from the smallest subcompacts to the full-sized combat size. The combat sized 9mm (CZ-75B) shoots anything I put in it with a good bit od consistency, i.e. there is no great difference in where I aim and where the bullet hits. But the smaller the pistol, the more difference I notice between *P*oint *O*f *A*im and *P*oint *O*f *I*mpact, with the lighter bullets hitting lower. All of my subcompacts shoot 147 grain bullets nearest to the aiming point. With the improved expansion quality of modern 147 grain bullets through shorter barrels, this makes the choice a no-brainer for me, so I prefer 147 grain in a all of my 9mm's.

'Your mileage may vary,' due to differences in guns or shooting techniques. My philosophy for a self defense handgun is that hitting the target trumps everything else. It's fun to muse over all of the different innovations that manufacturers claim will make their product better for you, but, realistically, nothing matters more than hitting where you aim, as early as possible, during any confrontation that actually results in a gun fight.


----------



## Murtaugh (Feb 15, 2016)

Bisley:
So what you're saying is that the weight isn't a factor, just where the bullet impacts?


----------



## Bisley (Aug 24, 2008)

No.

I'm saying it is enough less of a factor that I don't concern myself with it very much. My guns like 147 grain, and I like them, so that's what I use. I practice with 147 grain hand loads, and buy any good quality 147 grain SD ammo for carry and home defense.

If my pistol fired closer to POA with 115 grain, that is what I would use.


----------



## win231 (Aug 5, 2015)

Murtaugh said:


> Hi All:
> 
> I just got a Glock 19 that I'll be reloading for. In the past I've reloaded for .38 spl.
> As most of you know, the bullet weight ranges for the 9mm are basically: 115, 124 and 147.
> ...


Bisley's post is spot on. I'd also be more concerned with POA/POI. Remember, with bullet energy you don't get something for nothing. If a bullet is lighter, it will have more velocity but will generate the same energy as a heavier bullet going slower. A good example is 9mm vs 45 ACP - both are pretty close in Ft. Lbs. energy even though the 45's bullet is twice the weight.

9mm: 115 gr. bullet at 1150 fps = 340 ft. lbs.
45 ACP: 230 gr. bullet at 850 fps -= 370 ft. lbs.

Of course, the energy figures can be increased by using +P loads in either caliber, but again, the energy will still be similar.

If you're interested in the formula for calculating the energy of any caliber, multiply the velocity times itself, times bullet weight in grains & divide by 450,400.

And, here's a fun one. If you want the miles per hour of a bullet, multiply the velocity in feet per second by 0.6818. Example: 223 caliber. 3,100 fps x 0.6818 - 2,114 MPH.


----------



## Spike12 (Dec 10, 2008)

It comes down to E=MC{squared} So from that you can see that increases in bullet speed have a more significant impact on the Energy than bullet weight. If you and your gun can handle it; make both bigger. The old wooden battle ships used to be ranked by how many pounds of iron she could through at her opponent. 

A few direct points:
1) Lighter weight bullets will most likely recoil less and be more comfortable to shoot/practice and faster when regaining control for fast followup shots. 
2) Looking at the above Einstein formula, increasing the weight has the obvious benefits BUT the draw back the increased recoil - less comfort on a range day and slower recovery in prep for a 2nd shot. 

There is NO fast and firm answer. Those are the pluses and minuses. 

If you are considering self defense:
1) Bullet placement trumps EVERYTHING. A light bullet that hits is way better than a magic 300gn one that missed. 
2) A setup that is comfortable to shoot will let you practice more. Practice is life. 
3) You should practice with the same stuff you'll carry. You don't want surprises when the SHTF.


----------



## joethebear (Nov 24, 2015)

The equations are interesting basically making an easy to follow example. Find something both you and your gun like, keep in mind just because your "buddies" glock likes a specific kind of ammo it does not mean you and tours will in the same exact model. There are to many variables.
It is often said "no matter how fast you miss it does not count" find something you shoot well.

and have fun

Please be safe 
Joethebear


----------

