ORIGINAL: oldsmellhound
That's a really nice group with 67 grains - good shooting! I agree that rifles tend to have a sweet spot when it comes to various combinations of powder and bullets. Sometimes increasing or decreasing the powder charge by even a small amount can have ahugeeffect on accuracy.
Keep up the goodwork!
Yes 1/2 grain made a huge difference, I would say this is like shooting an extra 5gs of BP. I was expecting it to be bit tighter than 66g, but it fooled me, looking at the 66g target again that I shot 1 month agoand the 67gthat I shot todayand comparingthem side by side. I would say the 67g isabout 1/4" tighter, since the target on the left has both upper and lower bullets cutting the line, but eh one on the right has them inside the line Here is a side by side picture, 66g is on the left 67g is on the right.
Chap Gleason