Hi guys and gals,
I conducted a study on the effects of POI as related to ammo weight. Been wondering how much difference a tenth of grain makes at 100 yards, if any .
I began by running 5 of each weight over the chrony. There were 4 weights
JSB 44.5, 44.6, 44.9, and 45, 30 cal and using "RIP" (EVOL)
The spread was very small for the 20 shots. The high was 907fps, low 904 and average of 905. Right where Tom and others say that is the sweet spot.
I set the turret on 35 clicks, knowing that would be close, not worried about POI, just need to be on paper.
If you study the first target, 44.5, the elevation was spot on for 7 out of 9 shots. I was shooting from a mag and not my single shot tray. Notice this weight grouped to the left.
Target #2, 44.6 was also OK on elevation with a couple outliers but had grouped a tad closer to the aim point but still left of center.
#3, 44.9 is still good for elevation with 2 a bit high but not as tight a group as others and still left of center
Last target, 45 grain is a nice group, but for one that hit at 11:00, WTF!
No scope adjustments were made while testing. There was dead calm, no wing on this 7-8 AM shoot.
Anyway. I found it interesting how the groups migrated left to right as the ammo weight increased.
Thanks for reading this and give me thoughts as to why POI shifts right
I conducted a study on the effects of POI as related to ammo weight. Been wondering how much difference a tenth of grain makes at 100 yards, if any .
I began by running 5 of each weight over the chrony. There were 4 weights
JSB 44.5, 44.6, 44.9, and 45, 30 cal and using "RIP" (EVOL)
The spread was very small for the 20 shots. The high was 907fps, low 904 and average of 905. Right where Tom and others say that is the sweet spot.
I set the turret on 35 clicks, knowing that would be close, not worried about POI, just need to be on paper.
If you study the first target, 44.5, the elevation was spot on for 7 out of 9 shots. I was shooting from a mag and not my single shot tray. Notice this weight grouped to the left.
Target #2, 44.6 was also OK on elevation with a couple outliers but had grouped a tad closer to the aim point but still left of center.
#3, 44.9 is still good for elevation with 2 a bit high but not as tight a group as others and still left of center
Last target, 45 grain is a nice group, but for one that hit at 11:00, WTF!
No scope adjustments were made while testing. There was dead calm, no wing on this 7-8 AM shoot.
Anyway. I found it interesting how the groups migrated left to right as the ammo weight increased.
Thanks for reading this and give me thoughts as to why POI shifts right
