Help with Hatsan speed fire squirrel gun

Hey dudes. I am thinking of getting a hatsan speed fire for rabbit and squirrel. I am told both get 20 fpe 177 gets 1100 fps and 22 gets 800fps. Now usually I would say the 22 would be better for hunting but at these speeds I think the 177 would be significantly flatter shooting. I am really interested in hearing if 20 fpe with 177 can kill out to 50 yards. Most my game is within 35 yards but I just don't use 177 as often as when I was young. I know the 177 will do 35 yards but how about 45 or 50? Thanks guys. Would you guys get the 22 or would 177 be viable? 
 
I swapped your 1100 FPS into Chairgun for my CZ200 in .177 and if zeroed at 27yards, the 8.49g JSBs will drop .96". Doing the same for my FX Streamline in .22 and zeroed at 33yards, a JSB 16g pellet at 800 FPS will drop 2" at 50yards. 

If i'm bench rest shooting squirrels from my backyard picnic table then I'd get the .177. However, If I'm chasing squirrels in the woods, I'd get the .22 as it is more forgiving when you don't get that perfect kill shot. My 2 cents.


 
That's what I thought. I will just aim for the head if it's farther away. Thanks guys. So many people here have warned me about 177 not really being enough but I should have just used my experience. I remember killing a bird open sights with the 760 at 40 yards when I was 11 years old. It was smaller than a crow but bigger than a Robin. Could have been a giant bluebird but I can't remember. Anyway after that I got cocky. I started taking shots my dad warned me against. Everything died anyway if I did my part. I guess it's just a matter of how comfortable I am with the gun. I will have to shoot it often and get a feel for its accuracy but the energy itself will be fine if I can hit vitals. Sweet deal dudes I'm going to get the 177. I like the flatter trajectory. Take it easy. Everyone have a good Thanksgiving and remember to say a prayer before eating with your families. Take the time to count your blessings and tell God what your thankful for.