One of the most consistent features of accounts of the German Wars of Unification are the assertions that the Prussian possession of the Dreyse Needle Gun was decisive in and of itself because of its impact on Prussian tactical formation and the flexibility it gave the average infantryman.
Make no mistake, the Dreyse was a technological marvel for its time, it indeed gave the Prussians tactical flexibility and radically increased their rate of fire when compared to muzzleloader equipped armies of the time. The tactical innovations it allowed were few but important. Perhaps the single most important innovation it allowed was that it allowed the infantry to reload from the prone of lying down position. It also allowed the infantry to carry more ammunition as part of his basic load and made possible marching fire or the ability for infantry to fire and reload while on the march.
Reloading from the prone did several things the most important of which is it reduced the infantryman’s vulnerability to incoming fire. A not unimportant consideration when engagement ranges were rarely greater than 100 meters. Prussian infantry could carry more ammunition in the form of cartridges but this advantage was largely mitigated by their ability to fir more rapidly thus making a larger ammunition supply a necessity. The ability to engage in marching fire was also tactically very important because the use of marching fire did not allow the enemy a respite from fire while infantry was on the move as was the case when muzzleloader equipped infantry had to stop to reload. The last and most talked about innovation was rate of fire. Dreyse equipped infantry could fire 6-7 shots per minute compared to the 3 or more commonly 2 shots per minute of muzzleloader. These are the advantages.
As a weapon the Dreyse also had a few distinct disadvantages over contemporary muzzleloaders. First, and perhaps the biggest is that the Dreyse had, at best, an imperfect seal in the breech that allowed the hot gases from firing to escaper and flare into the face of the shooter. This is at a minimum distracting and can even injure the shooter. This is important because this defect caused most Prussian infantry to fire from the hip to avoid getting hot gases in their face during combat. Anyone who has any experience of marksmanship can appreciate the disastrous effect this tendency had on the quality of Prussian marksmanship in combat. In combat during the Danish, Seven Weeks’, and Franco-Prussian Wars the Prussian infantry did not inflict significant casualties on the enemy from rifle fire until they were in extreme close range because of the horrible marksmanship imposed by their preferred firing method.
The second disadvantage of the Dreyse was its firing pin. The Dreyse was called the Needle-gun for a reason. It’s firing pin was almost 6 inches long and shaped like a needle; hence the name Needle-Gun. The issue with the firing pin is that it was very fragile and tended to break during combat or sustained use thus making the Dreyse a very innovative club.
Lastly, the Dreyse was generally lacking in the accuracy department for those times when long-distance fire were possible. The Lorenz rifle used by the Austrians at Königgrätz was accurate out to roughly 800 meters while the Prussians with the Dreyse were lucky to hit anything past about 250 meters even when they held the rifle properly.
In conclusion, while the Dreyse was definitely an innovative weapon and a harbinger of what the future of military arms would be; it was not the revolutionary development that some historians would make it out to be. A balanced look at the Dreyse shows that just as any other military firearm, it has its advantages and drawbacks. The art of using any gun is the doctrine developed to exploit its strengths and minimize its weaknesses. The Prussians did this rather well in 1866 but in 1870-1871 the Dreyse was outclassed and it was only the superiority of Prussian artillery that allowed them to achieve tactical victories against the French Chassepot.