The problem is doing this without a chornograph has you just guessing. Feel includes noise and blast whether we want it to or not, and we just can't quantify speed based on feel. Recoil is also a poor indicator of speed, I have a 357 magnum load for example that is downright nasty on recoil yet it is a full 150 fps slower than a load that doesn't kick as bad with the exact same bullet, case and primer.
If you are using jacketed bullets try Universal Clays, very consistent and tolerant of low loading density.
If you are using lead Unique is a good choice.
Skip the Blue Dot, it needs more pressure than even +P will make to burn well and it is VERY dependent on position in the case for consistency. Tip the gun back and tap it, then carefully lower and shoot, I'll bet your BD loads feel very consistent and the chronograph will bear this out.