Aren’t The Benjamin Maximus And Discovery The Same Airgun?
Everyone seems to think that the Benjamin Maximus and Discovery are “the same”. OK, the Disco has a wood stock while the Maximus has one made of synthetic material. And the sights are different. But apart from that, they’re the same aren’t they?
Well, actually no. They’re not. Read on to find out why…
While the Maximus would obviously seem to be based on the Disco, the Benjamin Maximus and Discovery are actually different in many ways. Some of them quite unexpected…
When Hard Air Magazine reviewed the .22 caliber Maximus, we found significantly different shot curves between the Benjamin Maximus and Discovery when shot with the same pellets.
As you can see from the graph, the Benjamin Maximus has a lower maximum muzzle velocity, but a far more usable shot curve. The muzzle velocity does not fall as precipitously as the Disco and this will give much improved practical accuracy when shooting the Maximus compared to the Discovery.
But why is that?
One obvious difference is that the Maximus uses a longer barrel than the Discovery. This will increase the power of the gun. However, the purpose of this change was probably to compensate – in some part – for changes elsewhere in the Maximus.
To find more answers, we need to compare the internals of the Benjamin Maximus and Discovery.
Starting with the valve, we see that there are a number of obvious physical differences. The Maximus valve is red, for a start! But, more importantly, we can see that the valves themselves have physical differences.
When disassembled, we can also see that the Maximus and Discovery valve stems are completely different. In fact, the Maximus uses the valve stem assembly from the Crosman 760! It’s Part Number 760-201.
Crosman has a long history of using common parts among different models. This makes huge sense from an engineering and manufacturing perspective. Here, it indicates clearly that there are major differences in the valve design between the Maximus and Discovery.
And if there was any doubt about that, just look at the differences in the hammer springs!
There’s another major difference in the transfer port sleeve. Again, we can see that the Maximus and Discovery parts are different colors (Maximus is red).
But the pin gauges clearly show a small but significant difference in the internal diameter of the sleeve.
The Maximus transfer sleeve has an internal diameter that’s 16 thou smaller than the Disco. This means that the flow of air from the valve to the pellet is less in the Maximus, again contributing to that slightly slower, but flatter shot curve.
Comparing the Crosman EVP (Exploded View and Parts List) for the two guns reveals some other differences, too.
Surprisingly, the gauge ports are different too, although a simple visual inspection does not definitively indicate how.
Measuring the internal air passage with pin gauges showed a very slight difference. The inside diameter of the Discovery gauge port was 0.124 inches (124 thou), while the Maximus part was 122 thou. But such a small difference of 2 thou could just be found in a batch-to-batch variation for tolerances of these machined parts.
If there really is a 2 thou difference in air passages, that definitely is an indication of how hard Crosman engineers tried to improve the Disco’s performance!
Even more surprisingly, the diameter of the gauge port hole in the main air tube is different between the Benjamin Maximus and Discovery. This has no impact whatever to performance, so why change from the previous diameter that’s standard on the Discovery and Challenger? Dunno…
There are other differences between Maximus and Discovery parts, too. The bolt, bolt handle and safety all carry different part numbers from Disco parts. However, they seem to be parts of the same design but different finish (black or bright). The Maximus safety, for example, works just fine in a Discovery we tried.
And there are other minor parts changes associated with the different stock and front sights. Again, nothing that impacts performance.
So there we are. No, the Benjamin Maximus and Discovery are NOT “the same airgun”. Crosman should be given credit for making a lot of changes to the basic Discovery platform – far more than most people think – to develop the Maximus.