My "cold" first shot on a 7mm08 Savage is consistently 2" higher than the group that follows, beginning with the 2nd shot. It is very notable, as the groups (4 or 5 shots beginning with the 2nd shot) will be around 1".
Handloads, 42 grains Varget, 120 grain spire point Sierra, if any of that is important. I'm using a Rock BR front rest, and leather rear bag, using a wooden shim around the rounded forearm so that the rifle slides just like my 6PPC benchrest gun, which achieves in the range of 3/8" groups. The action is bedded. The lug is precision.
It is ALWAYS verticle stringing. The horizontal spread of all the shots is virtually always within 1". The first shot is just high.
I've tried shooting it uncleaned.
I've tried shooting it minimally cleaned.
I've tried shooting it extensively cleaned and de-coppered.
They are always high.
I can go up or down 1 or 2 grains of powder and I don't get near that change in verticle point of impact.
WHY? Can anyone give me a explanation for WHY that first shot is HIGH rather than LOW or RIGHT or LEFT?
I have a Mosin Nagant that is now down to 1" groups and its first shot is dead on. My benchrest 6PPC with a Shilen stainless match barrel - first shot is identical to others. My AR15 and AR10 -- no difference in first shot.
Any ideas?
Handloads, 42 grains Varget, 120 grain spire point Sierra, if any of that is important. I'm using a Rock BR front rest, and leather rear bag, using a wooden shim around the rounded forearm so that the rifle slides just like my 6PPC benchrest gun, which achieves in the range of 3/8" groups. The action is bedded. The lug is precision.
It is ALWAYS verticle stringing. The horizontal spread of all the shots is virtually always within 1". The first shot is just high.
I've tried shooting it uncleaned.
I've tried shooting it minimally cleaned.
I've tried shooting it extensively cleaned and de-coppered.
They are always high.
I can go up or down 1 or 2 grains of powder and I don't get near that change in verticle point of impact.
WHY? Can anyone give me a explanation for WHY that first shot is HIGH rather than LOW or RIGHT or LEFT?
I have a Mosin Nagant that is now down to 1" groups and its first shot is dead on. My benchrest 6PPC with a Shilen stainless match barrel - first shot is identical to others. My AR15 and AR10 -- no difference in first shot.
Any ideas?