December 13th, 2019
6minute read
The .40 died before it was born.
Thats a rotten way to start a fulfilling life, but there you have it.
Once it was commercially launched, the cartridge took off and blasted into the stratosphere.
Choosing the right chambering for your defensive handgun can be a tough decision.
More stopping power than the 9mm and more capacity than the venerable 1911.
Anyway, fast forward to the present, and it seems like everyone is running in the opposite direction.
The proof is in the pudding, right?
The 9mm (left) offers softer recoil, while the .40 (right) slings a larger slug.
Defensive bullets have to penetrate to adequate depths to perform their incapacitation function.
double-check you check out Yamil Sueds article on.45 ammunition for compact 1911 pistolsif thats your go-to handgun.
Do .40 and .45 make bigger holes?
From left to right: Barnes TAC-XPD +P 9mm 115 grain, Federal Premium HST 9mm 124 grain, Barnes TAC-XPD .40 S&W 140 grain, and Federal Premium HST .40 S&W 180 grain.
Does actual data from decades of use show statistically significant differences in metrics like one-shot-stops and shots to incapacitate?
In fact, all three calibers perform almost identically.
Apparently, the real world doesnt pay attention to tropes like Because shooting twice is silly.
The size difference between the 9mm (two left cartridges) and the .40 is immediately obvious.
If real-world street performance is roughly equal between the 9mm and .40, then why the big switch?
And then theres the recoil and ease of shooting factor.
But is the .40 really dead?
Modern bullet design has given the smaller 9mm (batch at left) a real chance to compete with the larger .40.
Consider some real data to explore the topic.
You know, science and math.
Lets start with power.
Tom tried out both Barnes and Federal offerings for his 9mm vs. .40 testing.
Kinetic energy reflects destructive power.
Think about a power drill as having lots of kinetic energy.
Momentum describes the ability of one object to whack and move another.
Momentum calculations, communicated as pounds-feet per second, weigh bullet weight and velocity more equally.
No big surprise here.
As most would guess, the .40 delivers more energy to the target than the 9mm.
The Springfield Armory XD-M 4.5″ pistol is offered in both .40 (shown) and 9mm.
These are substantially different concepts and are not included here for ease of comparison.
Think about the difference between a cap and ball revolver and a modern pistol.
The former is more of a slow push, while the latter has a snappy sensation.
Heres how the recoil energy numbers shake out for the same cartridges.
Since gun weight is an input factor, well assume that were shooting a Springfield Armory XD-M full-size pistol.
The 9mm weighs 29 ounces empty while the .40 tips the scales at 30.
So which one is right for you? Both the 9mm (left) and .40 are capable rounds, so it comes down to your personal preferences/needs.
Where It Counts
And herein lies the big reason that so many people are switching to 9mm.
For the standard 124- and 180-gr.
Is that a bad thing?
And its not like you dont get anything in return.
Just dont default to larger cartridges because someone says you have to.
The 9mm does similar, but not identical, things with less recoil.
But I still like it.
Pick which one you like.
Hate on the other.
Or, just own both!
