 Though the smoothbore guns were fairly modern, most of the other original armaments were antiquated, such as the 32-pounders, or modified, such as the 42-pounder "rifles" that were in fact old smoothbores that had been gouged out to give them rifling.These modified weapons were of particular concern to military commanders because they were structurally weaker and more prone to exploding than purpose-built rifled guns.Additionally, the close confines of riverine combat greatly increased the threat of boarding parties.