The Monstrum Blackbird 3x prism scope is the cheapest prism sight in the market under $100.
We purchased it and I checked out its durability, tracking, mounting system, illumination, and more to determine if it’s junk or the best budget prism sight you can buy.
Not every budget optic is worth the money, so I field-test the Blackbird 3x30 to see if it’s worthy of my recommendation or if it’s a hard pass.
Quick Overview...
What I Like: Cost
What I Don’t Like: Dim daylight illumination
Best Uses: Recreational Applications, Target Shooting, Some Hunting, Best for AR-15, Dual Illumination, Fixed Magnification
- Magnification: 3x
- Coatings: FMC
- Eye Relief: 3.5-3.0”
- Reticle: Circle dot
- Adjustments: 0.5 MOA
- Battery Life: 300 hours (approx.)
- Dimensions: 4.5” (L) / 12.2 oz
- Mount: Integrated 1.5” riser mount
My Verdict: The Monstrum Blackbird 3x30 prism scope is a budget optic that offers value to every buyer that intends to use it for recreational applications on an AR-15. The Blackbird performed exceptionally during field testing, and I recommend it for plinking, range use, and some hunting.
Why Trust Me?
After hundreds of hours of hand-testing red dot sights and riflescopes in the field and on the hunt, and thousands more hours researching, writing, photographing and creating videos about them, I feel I have earned the title of expert when it comes to optics!
Optics are not just my passion, but also my full-time job!
I get my hands on as many of the optics I test as possible (through buying, borrowing or begging!) and run them through their paces to make sure they will perform out in field.
Check out our optics testing process here.
Over a decade of experience target shooting, hunting, and troubleshooting my own red dot and scope problems has been integral in putting together this Monstrum Blackbird 3x scope review.
Who is the Monstrum Blackbird 3x30 Best Suited to?
On average, the Blackbird 3x30 will appeal to those looking to spend less than $100. As one of the cheapest prism scopes in the market, I think the Blackbird is best suited to recreational applications such as range plinking, target shooting, and perhaps some small game hunting.
Though the Blackbird produced exceptional results during field testing, I still doubt its long-term durability as a daily workhorse intended as a permanent optic solution on anything more than an AR-15. Also, given the numerous complaints about the short eye relief, it adds to my recommendation to mount it to nothing more than the .223/5.56 platform.
How Does the Monstrum Blackbird 3x30 Perform?
In total, the Monstrum Blackbird 3x30 prism scope is worth the money. It performed strongly in the field for close-range use from its decent optical performance to its, surprisingly, accurate tracking and zero retention even under abuse.
At first, I didn’t want to spend a whole lot of ammo on the Blackbird. I got it while it was on sale and barely paid anything for it, so I was reluctant to think much of it from the very beginning. However, it proved well worth the ammo and the time. I was so impressed by its initial performance at the range that I’ve taken the Blackbird out again and again.
One of my biggest worries was the adjustments. Sometimes really cheap optics don’t track, the adjustments are hard to follow if they’re mushy, and I’ve heard about junky sights having reversed turret systems. I’m pleased to report that none of that is an issue with the Blackbird.
The adjustments are in 0.5 MOA, and they track very well – the proof is in the pudding. That prairie dog target was a lot of fun to shoot up especially since those aiming dots are 0.375” in diameter – the 3 MOA dot covered that up plus some.
I was surprised that the adjustments have a positive feel to them and that they’re audible as well. They were a little easy to overshoot with, but nothing like some mushy turrets I’ve dealt with on other red dots in the same price range.
I think given its low price point under $100, there is a lot about the Blackbird that is impressive. The primary takeaway for me is that the Monstrum Blackbird tracks and holds zero. So far, it’s been a fantastic prism red dot sight for the AR-15.
Features & Benefits
Cost
In general, the market for prism scopes is slim compared to reflex red dot sights, and they tend to start at a higher cost than a reflex red dot too. The Monstrum Blackbird is an appreciated prism sight that’s mostly recognized for its low price point but proves its worth with its performance.
The Blackbird retails at around $100 but is often picked up for much less than that and has been as low as $50. This is clearly the budget category where not all optics are worth the low price. Target Tamers took the risk and purchased the Blackbird, and the investment has paid off.
For the money, the Blackbird 3x prism scope outperformed my expectations for cheap red dot sights in this category. Its quality and performance are commendable for a $100 scope and far exceeds what is expected of a $50 scope.
The Monstrum prism scope comes with a lifetime warranty, but it’s only valid on new products that are bought from Monstrum or from one of their official dealers. So, be careful where you might find that super incredible deal for it, you could unintentionally forfeit the manufacturer warranty.
Optics
The optics in the Monstrum Blackbird 3x prism scope are actually very good. I found the image to be sharper and clearer than I expected. Using the diopter made a huge difference for my far-sighted vision which is clearly an advantage of prism scopes versus reflex red dots.
With such low magnification, there’s not a whole lot of obvious aberrations that stick out. I didn’t see any color fringing, the depth of focus made for easy-on-the-eyes, natural observation, and the image is noticeably sharp from edge to edge for a budget scope.
Monstrum states that it has high-definition coated lenses and as a result, it produces a sharper image. There are no details on the coatings, or the process used for it, so it’s very likely that it’s at least Multi Coated, if not Fully Multi Coated, by universal presumptions.
The Blackbird 3x30 has a fantastic FOV of 39.3 feet – it’s wider than most 3x prism scopes. The diopter is smooth and easy to use. It makes all the difference in getting a very sharp view of the reticle too. However, it is easy to accidentally nudge it out of position, but at least it’s fast to get it back to where it needs to be.
There are a lot of complaints about the eye relief and having to mount the Blackbird as far rearward on the rail as possible. It does require you to remove a rear BUIS if you have one on there, and if you have your stock adjusted all the way out, you’ll probably find yourself creeping it.
The eye relief is stated at around 3.5-3.0 inches, but I crudely measured about 3.0-2.75 inches. Unlike a non-magnified reflex red dot, a prism scope is going to have eye relief, and I found it quite acceptable with the Blackbird. If you’re used to using a magnifier with a red dot, it should be a little bit better of an experience, but if you’re coming from a 1x reflex sight, it’ll take some getting used to.
I truly doubt there’s anything significantly noteworthy about the optics in the Blackbird, but it did great in various conditions. The glass is clear, the reticle is sharp, and I found the eye relief to be sufficient. Optically, it’s a better than average prism scope for the budget market.
Build Quality
There isn’t anything special about how the Monstrum Blackbird prism sight is made. It has a 6061 aircraft-grade aluminum housing. It’s complete with a Type-III hard anodized finish that has good scratch-resistant protection. Surprisingly for its price point, it’s also nitrogen-purged and waterproof.
The Blackbird is indeed sealed at its obvious weak points like around the turrets and the battery cap. But I wouldn’t recommend letting this get soaked as I suspect moisture could possibly penetrate the housing via the ocular bell, where the illumination knob is installed, and maybe around the objective bell. So far though, all is good.
I was willing to do a drop test on the Blackbird because I got it for so cheap. I don’t like dropping optics while it’s mounted to a rifle, but I did it – optic first. The Blackbird got some nice scratches that aren’t going to buff out, but nothing actually broke, chipped, or shattered. The mount is still static to the rail and screws are still tight.
Immediately after the drop test, I tested its zero expecting to be off. Unbelievably, it held. I feel like I got tighter groups after the drop test than I did sighting it in!
Usually, some sort of lens protection comes in the box as a standard accessory with a red dot sight, but it appears that the Monstrum Blackbird doesn’t come with any.
Overall, the build integrity has proven to be a strong point for the Monstrum prism sight. It’s unexpected to see a fog and waterproof scope for under $100, and the finish and housing have held up well to the abuse it’s seen during field testing. This unquestionably adds to its value.
Mounting
The mount on the Blackbird 3x prism scope has held up pretty well during my hands-on time with it. I really thought that this was going to be a weak spot in the design, but the mount has toughed it out. I still think it could be more robust, but I’m glad to see two integrated recoil lugs.
The screwheads are T15 and are torqued down to approximately 30 in-lbs. I’m not a Loctite person, but you could apply a little here if you’re experiencing some zero retention issues. I haven’t had that problem yet, but if I start getting it, the mount will be the first place that I look at.
For a co-witness, the mount puts the optical center at a 1.5” height. With my front A2 sight, it’s still visible in the sight picture even with the fixed 3x magnification. However, there’s no room at the rear to keep a rear BUIS on there unless you can get comfy with a nose to charging handle position. I do not recommend trying to co-witness irons with the Blackbird. Even so, to give you an idea, it does seem to put the reticle into an absolute co-witness position.
Although not obviously advertised, the Blackbird 3x also comes with a 0.25” spacer in the box. Added to the mounting system, it puts the optical height at 1.75” putting the front sight into the lower 1/3. I actually really like the spacer on there with the A2 front sight. If I were to move the Blackbird over to another AR-15, I’d take the spacer off and not even bother with it.
Size/Weight
The Blackbird 3x30 is a prism scope, and though they can get quite small, they’re still on the large end for a red dot sight. The Blackbird is about 4.5” long with the diopter all the way out. It’s 2.5” (approx.) tall to the turret with the mount, and around 2.5” wide with the knob and side turret.
The Monstrum prism sight weighs in at 12.2 oz, but it’s not any heavier than a red dot sight and a 3x magnifier combined.
It is rather bulky looking for what is considered a red dot sight, and it might be a little much and too high for something like a Ruger 10/22. However, on my M&P 15-22, it’s just the right size.
Even so, you should keep in mind its size and weight. It’s one of those things that is a make-or-break kind of issue for buyers, so you may as well know what to expect before you buy.
Best for CQB
The Monstrum Blackbird has 3x magnification, and its circle dot reticle with a 3 MOA center dot is great for easy reticle visibility. I think the reticle is best suited to close-quarter use inside 100 yards for fast target acquisition rather than precision.
You could definitely take the Blackbird to 200 yards and hit steel, but it’s not the kind of red dot you want to use to hold over, dial for range, or take beyond 200 yards in my opinion. I’d zero this for 50 yards and keep things close.
Battery Life
I really like that the Blackbird 3x prism scope takes a CR2032 battery to power the illumination. Those kinds of batteries are available everywhere and somewhat affordable. However, the battery life seems to be really bad.
The battery that came installed in the sight died inside a week and a half. I didn’t realize I had actually left the illumination. The next battery I replaced it with is still going strong, but I’ve been conscientious with making sure I turn it off when it’s not in use. I’m thinking the Blackbird has about a 300-600-hour battery runtime if it’s run continuously.
The nice thing about prism sights is that even if the battery runs dead during use, you still have a reticle to use. I honestly think that you don’t really need the illumination because the black etched reticle is super bold and highly visible. Plus, the illumination isn’t that bright in normal daylight conditions anyway.
Monstrum Blackbird VS Monstrum Marksman
The Monstrum Blackbird 3x and the Marksman 3x prism scopes are both similar in performance but very different in design. They both share the same reticle, 3x magnification, objective lens size, and according to the specs, the same FOV of 39.3 feet.
Though they have similar optical performance, they’re actually very different. Obviously, there’s the size component and how they look with the Marksman coming in on the larger side.
The primary difference I want to point out and why I prefer the Blackbird over the Marksman is the mount. The Blackbird has two recoil lugs that actually seat inside the slots of a Pic rail. I haven’t had any issues with the mount moving during recoil or in between range sessions.
The mount on the Marksman is weird and if there’s a reason for it, someone let me know what it is. The crossbolt pins on the Marksman mount are lopsided. This seems to be the case with all these Marksman models, so I’m assuming it’s intentionally designed to be this way.
Why I don’t understand it is because only the rear pin is low enough to engage and sit in the slot of a Picatinny rail. The front pin is too high and does not catch the rail at all. Even though there’s two pins in the base, the front pin is only there for lateral tension while the rear pin takes on all the forward and backwards stress. I can foresee some issues with that going forward.
The Blackbird doesn’t have this problem, so it’s a huge reason why I prefer it over the Marksman.
Limitations of the Monstrum Blackbird 3x30
Dim Daylight Illumination
Red dot sights are known for their long battery runtime and bright dot illumination, but the Monstrum Blackbird prism scope falls far short of this expectation. The illumination in both red and green failed to appear in daylight conditions unless the target was dark in color or in the shade.
Personally, I didn’t mind this because the reticle is exceptionally visible because of its black color and large MOA size. Though the illumination would be excellent for a reticle visibility in low light, I found that I actually didn’t need it most of the time.
Popular Questions About the Monstrum Blackbird 3x30
The mount could technically be replaced on the Monstrum Blackbird 3x prism scope even though it’s built in. The base can be removed but the issue lies in finding another mount with the same dovetail base and bolt pattern. As far as what I can see, there is no mount replacement for the Blackbird 3x.
In general, prism scopes are a better option over reflex red dot sights for astigmatism. The Blackbird 3x reticle is glass-etched and black which tends to be more compatible for astigmatic eyes to focus on. The diopter also provides a focused and sharp reticle for those who need dioptric correction.
The Monstrum Blackbird 3x prism scope does not have directional arrows on the turret adjustments themselves, but it does have them on the inside of the turret caps – anti-clockwise for UP and Right. It also references the adjustment value for each click, 0.5 MOA.
Accessories included with the Monstrum Blackbird 3x30 prism scope include a 1.5” mount, CR2032 battery, lens cloth, Torx wrench, extra mount screws, and a 0.25” spacer with longer screws.
The Blackbird 3x prism scope is covered under Monstrum’s Lifetime Warranty. It’s limited, so it’s only valid to the original purchaser since it must be a new product. The manufacturer warranty is valid if it’s purchased directly from Monstrum or one of their official dealers.
Best Budget Prism Scope: Monstrum Blackbird 3x
For the money, I highly recommend the Monstrum Blackbird 3x30 as a prism scope between the $50-$100 price range. It will be very difficult to beat for its decent optics, extremely sturdy build, and better than expected zero retention.
However, only for this price range am I willing to recommend it as a budget option. If you can afford something better, then invest in a higher quality prism scope.
But if you want something that will work for the AR-15 for some recreational shooting, the Blackbird is deserving of serious consideration if you’re on a budget.
Further Reading
