I still remember one hunting season in my early years(I was 15) when I got a shot at a big fat doe at around 40 yards and there was nothing to get a rest off of.I was using a Winchester 94 30-30 with iron sights,and I emptied it at that deer and she just walked away.I actually bawled.My Grandfather was with me,and he told me to either learn to shoot or quit hunting.I killed a deer the next year,and that one was running at full afterburner at about 75 yards,only that time I was using a scoped 270 and had literally worn out a Daisy BB gun and spent every evening either shooting the BB gun or groundhog hunting with the 270.That doe is responsible for my interest in guns and shooting.It takes a lot of practice to get good at shooting from any position,but offhand is by far the hardest to master.A lot of good comments have been made,and maybe I can add a little something.
Balance of the rifle can have a big effect on how shootable it is.I recently rebuilt my Remington model 7.After I got done with it,it weighs about half a pound less than it originally did.I contoured the barrel with a significant amount of weight added to it.At the other end,I lightened the rear part of the stock as much as I could,and it made the rifle's balance point move forward a few inches.It made a huge difference in how well I could shoot it offhand.
22's are usually very light,and that doesn't make shooting them offhand any easier.Also,the trigger can make offhand shooting harder if it's got a crunchy,creepy and/or heavy pull.But there's no replacement for practice.I like to hang ears of corn from strings and shoot at them,and as an added bonus,I don't have any trash to clean up,the deer do that for me.