A burning question about powder

[OLDMAN]

When I use Bullseye in my 12 inch 38 SPL barrel the powder burns very clean.  But, I get better groups using HS-6.  My question is: If   HS-6 burns dirty will all powders slower than HS-6 also burn dirty?  Now that I am asking questions, when I use HS-6 it will leave a solid line of residue down the full length of the barrel.  Other than being dirty does this have any other adverse effects.  The barrel is a SSK 38 SPL barrel.  Thanks

[Gregory]

I don't have any experience with the two powders you mention but I've used Unique and 2400 in my TC's and both are "dirty".  I've not seen accuracy problems related to this.

[Blackhawk44]

Once you get beyond powders like Bullseye, Titegroup and 231 (all basically serve the same purpose), powders will begin to leave residue, especially at 38 pressures.   As you get to rounds loaded to higher pressures (9mm, 357) they will begin to burn the medium and slower powders more efficiently.  The problem is that the 38 is strictly a low pressure round (in comparison to the more modern ones).