While both the Austrian cavalry and artillery arms of the Imperial Army were both well equipped, trained and well regarded, there is no doubt that the main body of the army - that is the infantry- was at a significant disadvantage not only in equipment, but more importantly in doctrine.

Now lets first take a look at the weapon in question: the Lorenz rifled musket, adopted in 1852 and named after its designer an Austrian artillery lieutenant. Now this inherently was not a bad weapon. It was a rifled musket typical of the time period, being extremely accurate at ranges of up to 400 yards and effective against formations at twice that range. It was by and large a fine rifle of the same vein used by the other Great Powers (excepting Prussia of course) at the time. However when compared with the Prussian breech loading Dreyse needle gun it fell painfully short as the Dreyse was capable of being fired 4 times faster, with the additional benefit of being able to be re-loaded from the prone firing position where the Lorenz had to be re-loaded standing up, exposing its user to enemy fire. Now the Dreyse gun was not some sort of secret weapon that the Prussians had- the Austrians knew all about it as Austria and Prussia had fought on the same side during Second Schleswig War against Denmark in 1864 and Austrian observers had noted the effectiveness of the Dreyse and had advocated for converting to breechloading weapons in 1865. However, the Austrian Ordinance Department was not convinced of the Dreyses qualities and after all no other Great Powers but Prussia were using breech loaders so why go against the grain?

Now we have compared the two weapons and despite the Lorenz muskets disadvantages, what really handicapped the effectiveness of the Austrian infantry was no the weapons they were armed with but how they used them.

Now this part requires some additional context. In the Second War for Italian Independence in 1859, the French had countered the Lorenz muskets superior range by deploying their infantry in loose skirmishing formations, which after a single aimed volley from close range, would charge in with the bayonet. This tactic was extremely effective as the curved trajectory of the bullets fired from the Lorenz diminished its accuracy when fired in volleys, allowing the French the close the distance between themselves and the Austrians without suffering catastrophic casualties. Compounding this was the Austrians tighter formations and reluctance to maneuver which made them especially vulnerable to bayonet charges. Now these defeats at the hands of the French had made the Austrians revise their infantry doctrine to place far too much value on shock tactics which emphasized the use of the bayonet and the élan of the infantry to carry the field and the day. However, when faced with the Dreyse needle guns rapid rate of fire these shock tactics nullified the Lorenz rifles superior range, causing the Austrian infantry to suffer very high casualties.

So there you have it. The Austrian infantry man was by all standards of the time brave and loyal in battle but bravery does not do much in the face of rapid firing breech loaders. I hope this helped answer your question! Please if you have any other follow ups do not hesitate to ask and I shall do my best to answer them.

Sources: The Battle of Konnigratz: Prussias Victory Over Austria, 1866 by Gordon A Craig and For God and Kaiser: The Imperial Austrian Army, 1619-1918 by Richard Basset.