DrMike
Ballistician
- Nov 8, 2006
- 37,314
- 5,979
Well, I awoke this morning to the promise of a bright day; the temperature was already at a balmy 3 C (37 F). The forecast was for a high of 5 C (41 F) and temperatures dropping on the following day. After a leisurely morning perusing the news, drinking a couple of cups of Tim Horton's, I decided to tackle the driveway to clear the snow before it all turned to ice. I cleared the drive, gathered my shooting gear and loaded the Tundra. It promised to be a leisurely day at the range. The temperature had risen to 5 C (41 F) and the sun was shining brightly. It is only a seventeen km drive to the range, I would be there and set up and have about four to four and a half hours until darkness would force me to shut 'er down. I noticed that when I arrived, it seemed somewhat cooler than when I left home twenty minutes earlier. Pulling my Kestrel out of my shooting bag, I discovered that it was -11 C (12 F). Somehow, that didn't bode well. The fact that dark clouds were obscuring the sun only heightened the sense that this could be an abbreviated range session. What it did mean was that I was assuredly not over-dressed for the weather. I had donned a wool sweater and a fleece vest, which is more than enough for me down in the valley when the sun is shining, the wind is still and the temperatures drop no lower than -5 C (23 F). I uncased the three rifles I had brought (a Sako chambered in .338 Lapua, my .30-06 and my 7X57), set up my chronograph, trotted through the snow to post some targets and prepared to pull the trigger. After the first round of shots, I took another temperature reading--it was now -13 C (8 F). At 1430 hours, it was -19 C (-2 F), snow was blowing sideways and it was surprisingly wet snow. I made a decision that is unheard of for me--the rifles could go home dirty today. Not that it mattered much, the solvents I use were all frozen by this point. I popped the top on a bottle of water, and it immediately froze. I glanced over at a bottle of Coke I had brought, and it was iced up as well. Time to pull a Hank Snow and get movin' on.
Despite the deplorable weather conditions, I did garner some decent data, and that made the trip worthwhile. All I would need would be a pot of very hot coffee once I got home and some nourishment to replace what was depleted due to heat generation. The Sako performed admirably. I'm doing load development on this rifle so the shop can burn turrets for a Huskamaw scope. I had previously shot a series of loads built with Hornady 225 grain SSTs and ReLoder 25. A maximum charge of 94.0 grains of RL25, produced a velocity of 2924 +/- 10 fps and a group of 0.55 inches. Today's workup ruled out H1000; velocities were good, but accuracy was ~2.00 inches across the spectrum of charges tested. My final set of loads were built with what has become a preferred powder in large capacity cases--Vihta Vuori N570. Velocities were exceptional, ranging from 3000 fps to 3172 fps. The initial load was quite disappointing, giving me a group greater than 3 inches. The mid-range charge, had lowered the group size to ~2 inches. I wasn't prepared to quit, as I have often witnessed that with this particular powder, near maximum charges produced astounding accuracy. And such was the case in this instance. The group measured 0.43 inches. It looked like this.
Yeah, I can live with that. We'll verify the data and then shoot to burn turrets next. However, because it is Christmas (and because it can be cold), it will wait until the New Year.
I have been working with the .30-06 for some time, looking for "the load." I've been shooting Hornady 165 grain InterBonds for the past couple of years. I'm gravitating toward a load built with 150 grain E-Tips. My first effort was rather unspectacular; the loads, charged with RL19, yield abysmal accuracy, though the velocity wasn't bad. The first loads tested today were built with RL17; and though they weren't abysmal, they certainly would qualify as appalling. Fortunately for me, I had constructed a second set of tests built with Hunter. Velocities are lower than I wished, but I can build them gradually, watching for pressure. Accuracy, however, was quite encouraging.
The velocity for this load was 2720 fps and the accuracy was 0.57 inches. Playing with seating depth and upping the charge will likely produce a load that I can enjoy. I should be able to approximate 3000 fps with this load, which would be quite a good all-round load for this area.
This was only my second trip out with the 7X57. The first trip yielded a group of 0.75 inches and a velocity of 2723 fps with the 140 grain AB and RL17. That could prove effective, especially for deer and caribou. It would be a good load for black bear, as well. Today, I was testing W760 behind the 140 grain AB. As charge increased, the group size moved toward a satisfying tightness, until I reached 49.7 grains of W760. At this charge weight, the velocity was 2783 fps and the group was 0.71 inches.
Again, playing with seating depth and upping the charge incrementally should produce a somewhat higher velocity and even tighter groups. This has always been a fun cartridge to shoot, and this rifle is a joy to play with.
Oh, yeah, the temperature is slated to drop to -27 C (-17 F) overnight. Wonder what the chance of the forecast erring in that case might be?
Despite the deplorable weather conditions, I did garner some decent data, and that made the trip worthwhile. All I would need would be a pot of very hot coffee once I got home and some nourishment to replace what was depleted due to heat generation. The Sako performed admirably. I'm doing load development on this rifle so the shop can burn turrets for a Huskamaw scope. I had previously shot a series of loads built with Hornady 225 grain SSTs and ReLoder 25. A maximum charge of 94.0 grains of RL25, produced a velocity of 2924 +/- 10 fps and a group of 0.55 inches. Today's workup ruled out H1000; velocities were good, but accuracy was ~2.00 inches across the spectrum of charges tested. My final set of loads were built with what has become a preferred powder in large capacity cases--Vihta Vuori N570. Velocities were exceptional, ranging from 3000 fps to 3172 fps. The initial load was quite disappointing, giving me a group greater than 3 inches. The mid-range charge, had lowered the group size to ~2 inches. I wasn't prepared to quit, as I have often witnessed that with this particular powder, near maximum charges produced astounding accuracy. And such was the case in this instance. The group measured 0.43 inches. It looked like this.
Yeah, I can live with that. We'll verify the data and then shoot to burn turrets next. However, because it is Christmas (and because it can be cold), it will wait until the New Year.
I have been working with the .30-06 for some time, looking for "the load." I've been shooting Hornady 165 grain InterBonds for the past couple of years. I'm gravitating toward a load built with 150 grain E-Tips. My first effort was rather unspectacular; the loads, charged with RL19, yield abysmal accuracy, though the velocity wasn't bad. The first loads tested today were built with RL17; and though they weren't abysmal, they certainly would qualify as appalling. Fortunately for me, I had constructed a second set of tests built with Hunter. Velocities are lower than I wished, but I can build them gradually, watching for pressure. Accuracy, however, was quite encouraging.
The velocity for this load was 2720 fps and the accuracy was 0.57 inches. Playing with seating depth and upping the charge will likely produce a load that I can enjoy. I should be able to approximate 3000 fps with this load, which would be quite a good all-round load for this area.
This was only my second trip out with the 7X57. The first trip yielded a group of 0.75 inches and a velocity of 2723 fps with the 140 grain AB and RL17. That could prove effective, especially for deer and caribou. It would be a good load for black bear, as well. Today, I was testing W760 behind the 140 grain AB. As charge increased, the group size moved toward a satisfying tightness, until I reached 49.7 grains of W760. At this charge weight, the velocity was 2783 fps and the group was 0.71 inches.
Again, playing with seating depth and upping the charge incrementally should produce a somewhat higher velocity and even tighter groups. This has always been a fun cartridge to shoot, and this rifle is a joy to play with.
Oh, yeah, the temperature is slated to drop to -27 C (-17 F) overnight. Wonder what the chance of the forecast erring in that case might be?
