The problem with bottling from a primary or secondary instead of using a bottling bucket, is that since you have patiently gone and let your beer settle and clear, in order to mix the priming solution and beer effectively
, you would have to stir it in the carboy..which would a) kick up all that nice sediment you have patiently let fall, b) possibly oxydize the beer.
Go to a hardware store and get a translucent or white bucket...but look for one where the 5 gallon mark falls way below the top of the bucket. Usually it will say 5 gallons at 3rd band from the top. (oh get the lid too....I totally regret not getting it when I did.)
Then get a spigot and make a dedicated bottling bucket. It really defeats the purpose of both a long primary/no secondary or a secondary if you have to stir up all the nice sediment you patiently waited to settle just so you can have consistent carbonation.
Mine is the translucent Leaktite brand 5 gallon container with the gallon and liter markings from Homedepot.
Here's a pic of mine from my bottling thread.
And then ONLY use your bottling bucket AS A BOTTLING BUCKET, and you won't have to have this issue again.
If you can't find a spigot today, then rack to the bucket and fill the bottles with the autosiphon, if that's what you wanna do, but you really should move it to a vessel where you can evenly integrate the priming solution and the beer.
But if you try driectly from the primary you will have unsatisfactory results and possibly even cardboard tasting beer.