Extreme Spread is my Nemesis (at least it was yesterday)
Blew the dust off the old 22-250 Ackley rifle yesterday and took her out to the range. Last time I had her out was this time last year and she didn't shoot the greatest with the ammo I had (handloads from P.D. trip out west in 2006). I had 50 rounds left from that same batch of ammo that were loaded a little lighter (39.2gr H4350 compared to my usual 39.4gr) so I thought I would take them out and run them over the chronograph to see what was going on. Besides, it was a great excuse to be at the range on such a beautiful spring morning.
http://img.photobucket.com/albums/v6...c.jpg~original
I started at 100yds and the old girl was shooting pretty good, but it seemed I would have one bullet go astray in each group, a result of that rounds velocity being way higher or lower than the rest.
http://img.photobucket.com/albums/v6...h_100yds-1.jpg http://img.photobucket.com/albums/v6...h_100yds-2.jpg http://img.photobucket.com/albums/v6...h_100yds-3.jpg
http://img.photobucket.com/albums/v6...h_100yds-4.jpg http://img.photobucket.com/albums/v6...h_100yds-5.jpg http://img.photobucket.com/albums/v6...h_100yds-6.jpg
The trend continued at 200 yards...
http://img.photobucket.com/albums/v6...h_200yds-1.jpg http://img.photobucket.com/albums/v6...h_200yds-2.jpg
http://img.photobucket.com/albums/v6...h_200yds-3.jpg http://img.photobucket.com/albums/v6...h_200yds-4.jpg
During the course of my shooting I had noticed the velocity seemed to be varying quite a bit, but it wasn't until I got home and downloaded the data to my computer that I saw just how bad it really was.
http://img.photobucket.com/albums/v6...ChronoData.jpg
As you can see, Group #4 (String 6) was the only string that was consistent for all five shots and it clearly shows in the group size. Fortunately this was the last of the ammo I had from that batch 9 years ago so hopefully some fresh precisely measured loads will have her shooting in the high 2's and low 3's like she usually did in the past.