Downgrade/Jailbreak Iphone 4s with iOS 6.1.3?

I think jailbreaking 6.1.3 on the 4s is not possible yet, can you downgrade to like iOS 6.1.2 for example though?

I think Apple stopped seeding iOS 6.1.2 through iTunes. Even if you download iOS 6.1.2 off the internet it may or may not work.

No you can only downgrade a iphone 4 if you have the shsh blobs saved