Diamondback DB9 GEN 4 Review

Pocket pistols have been popular nearly as long as firearms have been available. From pepperboxes to derringers, men and women have frequently sought a small handgun that could be carried in deep concealment for self-defense.

In this Diamondback DB9 GEN 4 review, I take a look at the reliability and usability of this tiny 9mm handgun developed for just such a use.

As the modifier GEN 4 suggests, the gun I’m reviewing is an updated version of the original DB9 pistol. Is the new gun a substantial improvement compared to the first generation pistol? Definitely.

General DB9 GEN 4 Pistol Information

The DB9 GEN 4 is a polymer-framed 9mm subcompact pistol. It is less than 0.9″ wide and holds 6 rounds in a magazine. In short, it is a very flat, easy to conceal handgun chambered for a respectable defensive cartridge. It could be considered an alternative to the classic J-frame for pocket carry.

Where to buy a Diamondback DB9

Where to Buy the Diamondback DB9 Gen4

The Diamondback DB9 GEN 4 is available through our affiliate links here:

The original handgun hit the market about 10 years ago, and I had a chance to review one then. Now, I’m taking a look at the GEN 4 pistol and comparing it to the original.

Features & Styling

For many shooters, the size of this pistol will be the initial attraction. It is relatively small at just 5.7″ long and 4″ tall with a flush-fitting magazine. With an empty magazine, the gun weighs 13.4 ounces.

Diamondback Firearms DB9 Gen4

In my view, one of the key measurements of this pistol is its thickness. At the widest part, the gun is only 0.89″ across. The slide has a maximum width of 0.81″. Some people carry wallets that are thicker than this pistol.

Even with its small size, Diamondback Firearms still managed to fit this pistol with a 3.1″ stainless steel barrel.

I envision this as a potential replacement for the J-frame revolver. Many people carry a 5-shot .38 Special in a front pocket due to its ease of carry and concealment. But the DB9 GEN 4 offers a longer barrel, more rounds between reloads, arguably more effective self-defense ammo and a flatter profile than a Smith & Wesson 642. Heck, the DB9 GEN 4 is even lighter.

Texturing is on the front and rear of the frame in the grip area. The slide, also made of stainless steel, has deep serrations on the front and rear for a positive grasp. The slide has a QPQ black nitride finish.


The DB9 GEN 4 is a double-action-only, striker-fired pistol. Each time you stroke the trigger, you get a consistent pull. The trigger is round with a smooth face.

DB9 Trigger

There is a considerable amount of take-up with a fairly short pull. Using an average of 10 pulls with a digital Lyman trigger pull gauge, I measured the pull weight to be just under 7.4 pounds.

When the trigger breaks, the trigger is up against the frame of the pistol eliminating any potential overtravel. The reset is relatively short.



That’s probably the best word I can use to describe the sights on the DB9 GEN 4 pistol. Many, if not most, sights on pocket pistols are tiny and difficult to use. When you add in how your vision is altered by body alarm response in a self-defense encounter, a lot of subcompact pistol sights are functionally useless.

Diamondback DB9 Gen 4 Sights

Diamondback Firearms elected to go with full-size sights with Glock-compatible bases. That means you can swap them out for darn near any other design on the market if the factory sights don’t ring your bell.

Before you rush over to the Brownells catalog to find a new set, take a good look at the stock sights. They’re pretty good. Actually, they are possibly the best factory 3-dot sights on any subcompact pistol currently on the market.

Diamondback uses a wide U-shaped rear sight that allows for quick sighting in a defensive situation. While potentially less precise, the design should allow you to get your pistol on target rapidly for center mass hits. This style sight is what many aftermarket companies are moving toward because of its efficiency.

DB9 Gen 4 Holsters

Having a gun for self-defense is only part of the equation. One of the other variables is having a quality holster. Fortunately, Diamondback works with holster companies to make sure there are concealed carry options available for you.

DB9 Holster

Diamondback Firearms lists six companies that support this pistol:

  • Black Point
  • Black Rhino Concealment
  • Crossbreed Holsters
  • Dara Holsters and Gear
  • Kester Farms
  • Pyntek

However, there are a few more companies that are also worth considering: Blackhawk and DeSantis. Both of these companies offer pocket holsters that fit the DB9 GEN 4. Of these, my top choice is the DeSantis Nemesis.

I’ve used various sizes of the Nemesis for all kinds of pocket guns including my 642 and Kahr CM9. The Nemesis works well, is durable and is affordable.

I will be adding a full Diamondback DB9 Gen 4 holster page shortly.


Diamondback Firearms offers a limited lifetime warranty on the DB9 GEN 4. To obtain warranty work you would need to have a proof of purchase and there may be some handling charges you would be responsible for. Of course, Diamondback doesn’t cover anything you try to fix and make worse. Also, you need to adhere to the correct ammo for the gun. Running “Super Blaster Double ++P++” will void your warranty – just like it will at nearly any firearms manufacturer.


Here are the factory specs on the DB9 Gen4:

Actionstriker-fired DAO
Barrel Length3.1″
Overall Length5.7″
Weight (unloaded)13.4 oz
Height (w/ flush-fitting magazine)4.0″
Gripblack polymer
Slide FinishQPQ black nitride
MSRP (at launch)$269
MSRP (current)$305

Range Testing

When it comes to defensive firearms, reliability is king. If a gun is not reliable, it is not suitable for use in personal protection.

The DB9 Gen 4 proved perfectly reliable with more than 10 different 9mm loads. These loads were a heavy mix of hollow point and practice loads, both standard velocity and +P. All of them ran flawlessly.

Range Testing the Diamondback DB9 GEN 4 9mm Pistol

Accuracy was acceptable for a subcompact pistol. Most of the loads fell within a 2″ – 2.5″ range for 5 unsupported shots at 7 yards.

Subcompact pistols are small by their very nature. If you have large hands, this gun will seem tiny. Make sure you get a good feel of it in the store so you know what you are getting. While I had no problems shooting it, others may.

My primary concern I had on the range with the DB9 GEN 4 is the felt recoil. In a small gun, 9mm cartridges can feel snappy. Due to the thin nature of this pistol – about 0.89″ at the backstrap – the recoil is pushed into a narrow area of the hand. As I shot round after round, that portion of my hand became tender from the repeated impacts.

For a little practice at the range, the recoil won’t bother a regular shooter. However, if you plan on shooting an advanced pistol class with the DB9, you will feel it.

A secondary concern for me is the magazine release button is small and difficult to activate. This is a double-edged sword. If the button stood proudly above the edge of the frame, there is ample opportunity for it to be depressed while carried. Alternatively, it being hard to access makes fast reloads difficult.

Statistics compiled by John Correia at Active Self Protection indicate reloads are rarely made during non-law enforcement deadly force encounters. This suggests having an easy to access magazine release is less important than having one that will not activate accidentally when pocket carried.

I would prefer an easier to activate release, but you may be quite comfortable with how the DB9 GEN 4 operates.

Ammunition Performance

Blazer Brass 124 gr FMJ1,011 fps281 ft-lbs
Federal HST 124 gr JHP +P1,078 fps320 ft-lbs
Hornady Critical Defense 115 gr FTX1,052 fps283 ft-lbs
Remington UMC 115 gr FMJ1,010 fps261 ft-lbs
Remington UMC 115 gr JHP1,038 fps275 ft-lbs
SIG SAUER Elite 115 gr FMJ1,136 fps330 ft-lbs
SIG SAUER V-Crown 115 gr JHP1,123 fps322 ft-lbs
SIG SAUER V-Crown 124 gr JHP1,079 fps321 ft-lbs
SIG SAUER V-Crown 147 gr JHP934 fps285 ft-lbs
Speer Gold Dot 124 gr JHP1,016 fps284 ft-lbs
Winchester USA Forged 115 gr FMJ1,012 fps262 ft-lbs

How Does it Compare?

While there is an obvious relationship between the two guns, the GEN 4 version of the DB9 is a significant improvement when compared to the original. Here are a few of the highlights:

ammunition – While both guns are chambered for 9mm, only the GEN 4 is rated for +P loads. If you are not familiar with the term, +P is an industry designation that indicates when a cartridge generates a chamber pressure beyond that of the standard load. Many self-defense loads are +P rated and these can be shot in the GEN 4, but not in the original pistol.

Note: SAAMI, the industry entity that sets cartridge standards, has a specific range of pressures deemed safe for a 9mm +P rating. If a load is rated as +P+, it generates pressures in excess of all SAAMI specifications and should not be fired in this handgun.

Also, Diamondback Firearms recommends only bullet weights of 124 grains or lighter in the original pistol. According to Walker, there are no such restrictions on the newer pistol.

sights – This is another huge improvement for the pistol. The original DB9 had tiny sights that were difficult to use. With the GEN 4, Diamondback includes serious combat sights on the gun and has used Glock-style bases to allow for a broad range of upgrades if desired.

recoil spring assembly – The GEN 4 pistol uses a captive recoil spring. This makes field stripping and assembly much easier.

Another note about the recoil spring is that it is noticeably lighter on the GEN 4. I’ve seen several people struggle to run the slide on the original DB9. In contrast, the GEN 4 slide doesn’t need nearly as much strength to properly manipulate.

trigger – According to the company, the newer pistol has an “improved trigger pull and shorter reset.” I’m a bit mixed on the newer gun’s pull.

The original gun had a long but consistent pull throughout the stroke. Using my Lyman trigger pull gauge, I measured my original DB9 at 5 pounds 15 ounces on a 10 pull average.

The new DB9 variant has a generous amount of take up followed by a short, but heavier pull. I measured this pull at 7 pounds 6 ounces on a 10 pull average.

Reset is much shorter in the GEN 4 model, so you do not need to let the trigger go fully out before pulling it again.

slide stop – A slide stop is a standard feature on most pistols. However, the original DB9 did not have one. Diamondback Firearms changed this on the GEN 4. Now you can lock the slide back and see an empty chamber. I’m quite pleased with this change.

DB9 Magazines

magazine base plate – Diamondback uses an updated magazine base plate design with a little more real estate for your hand. The size difference isn’t much, but it feels much better. It looks better too.

Final Thoughts

Reliable and compact, the updated DB9 pistol is worth considering if you need a subcompact pistol for very discreet carry. The larger sights, ability to run +P ammunition and the inclusion of a slide stop combine to make this the best DB9 yet. Throw in a sub-$270 price tag and a lifetime warranty, and you get one of the best values in defensive pistols on the market today.

Its only significant drawback is what makes it appealing: the size. If you have large hands, the gun probably won’t fit very well. But, this should be expected. The only thing I didn’t like was that the thinness of the backstrap directs recoil into a narrow slice of the hand. During an extended shooting session, this can become uncomfortable quickly. However, this is the tradeoff for having a defensive pistol that can disappear in a pocket.

If you think the Diamondback DB9 makes sense for your needs, consider picking one up through our affiliate links below. It helps me keep the site running.


The DB9 GEN 4 offers a number of significant improvements over the original including the ability to run 9mm +P ammunition, the addition of a slide stop and much larger sights that are Glock base compatible.

My test gun ran flawlessly with all kinds of hollow point ammunition. Backed by a limited lifetime warranty, this $269 pistol is one of the smallest 9mm pistols on the market. Although extended use can beat your hand up, in return you get an extremely concealable handgun.

Last update: August 29, 2021


Diamondback provided the loaner gun used in this article without charge. I did not keep the gun and returned it to the company.

I did not promise to do a positive review of this pistol, nor did anyone representing Diamondback ask me to do so. I received no money or other compensation for this review.

I have no financial interest in Diamondback Firearms or any other gun manufacturer.

GunsHolstersAndGear.com is a for-profit website. I do not charge readers a dime to access the information I provide.

Some of the links on this page and site are affiliate links to companies like Amazon and Palmetto State Armory. These links take you to the products mentioned in the article. Should you decide to purchase something from one of those companies, I make a small commission.

The links do not change your purchase price. I do not get to see what any individual purchases.

If you have any questions about this disclosure, or if you have some thoughts on my DB9 GEN 4 review, please leave them in the comments section below. I try to respond to everyone in a timely manner.

Please keep all comments civil. I try to run a family site and will edit or trash comments loaded with profanity or personal attacks on others. The shooting community is a fun place – let’s keep it that way.

59 replies on “Diamondback DB9 GEN 4 Review”

I have both DB-9s and the Gen 4 is definitely the best!
It is a real life saver and should be compared to the other nines!
Sig, Glock and even Kimber have nothing on this little jewel..
You will appreciate the size,weight and ease of concealment .
You can’t go wrong with this pistol! Your Retired Firefighter’s honest opinion!

Took my new db9, gen 4 out to range for a test run and noted the trigger pull was horrible I’m used to pulling the trigger and the pistol shooting but due to it’s extremely long creep I thought something was wrong and at 21′ only 3 rounds out of 12 found the target. That being said do love the size and the grip wrap helped control ii but will be replacing it with one that has a decent trigger

J&J Custom makes a great pocket holster for the db9. As for the rough shooting experience on this little guy, you do kinda get used to it. It made my forearm sore after 50 rounds. I shoot the Springfield Hellcat all the time and its recoil has nothing on this little fella.

Leave a Reply

Your email address will not be published. Required fields are marked *