Is it possible to go back to iOS6 from iOS7 in iPhone 4?

I got an iphone 4 and updated it to iOS 7… The OS was laggy but i thought the next update will fix it… But i checked my friend's iphone 4s and found it to be as smooth as ios 6… I figured it's a problem with my hardware so it's never gonna get fixed… Is there a way to downgrade to ios 6?
why update the iph 4 if the hardware couldn't handle it? I'm disappointed with apple… They probably did this intentionally to force users to upgrade…
now my iphone 4 feels like a low end android phone… I was perfectly happy with iOS 6…

Yes you can download IOS 6 and installing using Itunes all you have to do is plug in your Iphone 4 and go to your device indicated on the high left corner and from there you can navigate to your summery of the Iphone 4 after that you press and hold shift on [restore iphone] (which may restart your device but save it in the cloud) and a window will come up from holding shift on restore iphone after that's done you get the file you just downloaded (The IOS 6 file) and put it into the window. And just click on and press [Open] after that it will do the rest here are some links of people explaining also where you can download the file, I hope this helps.

You're right, that's exactly what they did. A client of mine is experiencing the same issue on a 4. We're trying to figure out the issue now.

We're coming up with a factory reset, to do a fresh install of iOS 7. You'll lose data, but most should restore after iCloud backup. Try that out

It is possible to downgrade back to IOS6 as my friend has done that I'm not exactly sure of the ins and outs of how to downgrade rather than stay at it but if you google it I'm sure something should come up.