Tinker,
Sounds like you are unintentionally doing a tuck cast.
A tuck cast is where you purposely over power your cast causing the fly line to hit the end of the cast but still have too much energy in it. It will cause your fly to bounce back toward you. A good tuck cast will actually cause the fly to shoot down toward the water.
So now that you know what is causing it, excess energy in your fly line, there are potentially a few causes. It may be a single issue, or may be a collection of various issues all working in tandem to cause this excess amount of energy.
I think, based upon what you have described thus far, that it could be your leader/tippet setup together with your casting stroke.
There is a reason why trout leaders, for the most part, are tapered. It allows transferring the energy created from your cast to your fly in a smooth almost uninterrupted motion or transference. It also functions as a way to dissipate energy. As the energy moves down your tapered leader, there is less and less of it for the energy to travel through, so it starts to dissipate. Thus with the right amount of power in your cast, it is simpler/easier to get a good transfer of energy to your fly to give a good presentation.
Now, that being said, one with enough practice and experience, could do perfectly fine casts and get wonderful presentations with non-tapered leaders. And each has its own purpose and application. All I am saying is that it is typically easier to get a good presentation with a tapered leader, due in part to how it transfers energy.
Also, length of the leader is an important factor. The shorter the leader, the less distance your cast energy has to travel before it hits your fly, which directly translates into less opportunity to dissipate any excess energy. Thus your fly gets blasted with extra energy and it snaps back to you.
There is also the diameter of tippet vs leader end. If your leader end comes down to a say 6x size, but you are attaching 5x, 4x, or 3x tippet (any size tippet of large diameter than the leader end), you are essentially adding a thicker piece to a thinner piece right at the end of the whole thing. The little bit of energy that is at the end of your leader now has to push through something thicker than what it is traveling through right before it hit your tippet. You are going to lose some energy, thus giving your presentation issues. And the opposite holds true too. If you go from a thick leader end, let’s say 3x, down to a smaller tippet of 5x or 6x or maybe even 7x, then the amount of energy at the end of your leader before hitting your tippet is going to over power the much much smaller diameter tippet and again, you will have presentation issues.
Another thing to consider is the material. It really doesn’t play into everything too much, but it is something to consider. Every material has its own density. And the denser a material is, the easier the transference of energy is. Think about sound going through air vs. water. Mono (Nylon) and Floro are made of different materials, and their density is different. If you are going from one that transfers energy very easily, to one that doesn’t, you are going to have presentation issues. And vice versa, if you are going from one that doesn’t transfer energy very easily to one that does, again, your presentation is going to have different consequences as well.
Think of it like this: if you are driving a camero (or any sports car of your liking) and are zipping along a nice smooth race track, then all of a sudden the nice smooth race track converts to a dry sandy beach, what is going to happen? You are going to lose your momentum quite quickly because you are now driving across a different medium, or material, one which doesn’t allow your tries to have sufficient traction to give you the speed needed or desired. Your transference of energy from the car to the surface is not as efficient as it was when you were driving on the race track. Does that make sense? Now, again, really the differences in mono vs. floro are quite small, but it is something to take into consideration.
I personally have my typical trout setup as such (regarding leaders and tippets)
Leader: 9 ft tapered mono. Depending on the stream, fish, season, etc. I will vary my leader from 3x – 6x. I find that the 9 foot length really allows me to do some very good presentations and it helps with the transference of energy very well, while dissipating that little extra “oompf” that perhaps I gave it right at the end of my cast when really I didn’t need to.
Tippet: I use mono tippet. If I used a floro leader, I would use a floro tippet. I have floro tippet with me when I go fishing but rarely use it. I tend to stay with in a 3 level range of my leader when choosing my tippet size. For example: if I have a 5x leader on, I will use either a 5x tippet or 6x tippet, and if I truly need or want to go up, sometimes I will use a 4x tippet. So, I use tippet that is either one size higher, same size, or one size lower than my leader size.
You should also consider if you are using heavy flies (like bead-head flies, double rigs, hopper dropper rigs, etc.) on light leader/tippet setups. The heavier your fly setup, the “heavier” your leader and tippet setup should be. It allows for better turn over, it has more mass to it to help cut through the wind, and it allows you to better manipulate your rig setup.
Maybe the biggest thing affecting your fly presentation is your casting stroke. If you add too much power to it right at the last moment in your forward stroke, right before you send it flying to present it to the fish, it will have too much energy in it. Too much energy will over come everything describe above and cause your fly bounce back to you. Perhaps letting up a little on your forward stroke will help to some degree.
Here are some links that provide information regarding leaders and tippets:
Hopefully this information will help you and not confuse you. Sometimes (actually a lot of the time) I give more info than what is really needed. Just ask my wife, hahahahahaha. :lol:
Take care man and have at it!! Good luck out there.
-Spydey