Saturday at the Range
Well, the weather man said 40-60 degrees, but when I got to the range at 7:am Sat Morning, it was 29 degrees. Not a cloud in the sky.
It never got above 56 all day, but the Sun was shining, and the humidity was no higher than 30 percent most of the day.
We started out with that upper end load that shot so well the last time out, and Mr Verticle was camped out on the target. I was thinking we were too hot, but as we went down, it got worse. Not real bad, but not real good.
Then I set my Chrono up, (Ohlear 35P), and discovered that the velocity was down quite a bit. The 31.8 grn load was only going about 3430.
So, I told Vic Smith that maybe we needed to up the load to match the 3470 or so that shot so good last time out. We did, (32.4 grns), and bingo, Mr Verticle left and Mr "zero" took his place. I shot some nice ones, then nailed a really nice zero with my Sporter. I had a 6th shot left, and it put another shot in the group with no affect. I figure it went about .070.
I then set my Rail Gun back on the bench, and using the exact same load, nailed a 10-shot group that was no bigger than .140. Nice round hole.
One other note. The velocity in the Rail Gun, (23.5 inch barrel), averaged about 3480, but the velocity out of the 21.5 inch Sporter was barley 3400, actually about an average 3390.
With N133, I see only about a 30 fps drop between the Rail and the shorter Sporter barrel. I agree with Mike, we need to wait untill warmer weather to see how much affect a 30 degree difference will make. I can darn sure make it shoot at 55 degrees, with a lot of powder. I suspect that when the weather warms up, this stuff will be just about ideal.
Incidentally, that 32.4 grn charge comes just a tad over 1/2 way up the neck with a 8 inch drop tube and a slow trickle.........jackie