 Problems were also found with the Littlejohn adaptor fitted to the 2 @-@ pounder to increase its range and penetration power ; after they had been fitted the adapters could not be removed , and could only fire specially designed armour @-@ piercing rounds , which took time to manufacture . 
 Problems <a href='uninflect' title='1'><mark>were</mark></a> also found with the Littlejohn adaptor <a href='uninflect' title='2'><mark>fitted</mark></a> to the 2 @-@ pounder to increase its range and penetration power ; after they <a href='been_done' title='3'><mark>had</mark></a> been fitted the adapters could not be removed , and could only fire specially designed armour @-@ piercing rounds , which took time to manufacture . 
Problems was also found with the Littlejohn adaptor fit to the 2 @-@ pounder to increase its range and penetration power ; after they done been fitted the adapters could not be removed , and could only fire specially designed armour @-@ piercing rounds , which took time to manufacture .