Stringing shots

[catman]

I took the old T/C Renegade .54 cap lock out yesterday, it's got the 1:48 twist and the barrel is not the best in the world but it works.
Set up at 50 yards and started. .530 Hornady ball,.18 red pillow ticking using good old T/C bore butter (it works) and 75gr 2F. First shot nuts on (spit patch wipe and turned over and done again), second shot same line just 1/2" down same cleaning, third shot 1/2" below the second hot (still the same line),same cleaning and then 4th,5th & 6th shot all strung in a perfect string a 1/2" below each hole North to South?
I could not have drawn a more perfect (I) on paper.
The old barrel is pretty rough about the last 12", it was this way when I got it (for $45) (I've worked on it as best I could with 1000 steel wool & machine oil). Most say that's the most important part of the barrel. It usually does about a 3" group @ 50 yards. Just thought is was strange to string like that for the first time. I wish I could have shot more it started to get dark so I loaded up came home cleaned her up, I guess I'll see what happens the next time we go out.
A little puzzled I guess :hmm:

 

[trent/OH]

I'll go out on a limb and guess the sun was out, and at your back. If so, and I were a shade more mathematically inclined, I could probably work out your reloading speed based on the half-inch increments of your shots. That's my suspicion: the sun on the sights and/or target was causing such perfect stringing.

 

[wtilenw]

A difference in the amount of lube on the patch, shot to shot will cause vertical stringing too.

 

[squirejohn]

I remember reading somewhere that increasing the powder charge will "cure" vertical stringing.

 

[FishDFly]

A uniform pressure, shot to shot, must be used to seat the bullet. Variation in seating pressure causes vertical stringing of the bullet impact points.

RDE