kilotanker22
New member
So I went to the range today and tested the same load that seemed to work so well a few days ago. This time instead of the 5 times fired cases I used once fired cases. Not all of these cases were fired in this rifle. I found that with the same die setting the shoulder was set back several thousandths further than with the other brass. I assume this is due to the other brass being more work hardened and these being softer. I also saw around a 14 fps increase in average velocity and a slightly higher velocity spread. I am also assuming this is due to the softer brass.
Another possibility is that although this is all Winchester brass collected from their OTM Range ammunition, they do not all have the same headstamp. I did notice that all of the shots that shot higher velocity opening up the spread were stamped "USA 6.5 CM". The others were much more consistent with the results I had a few days ago. Actually the ones stamped "Winchester" were only a few fps different than what I shot the other day. So from now on I know that the two cases are not the same. Even though they are both Winchester cases. From now on I will sort them by stamp.
Aside from that. The load was shooting pretty well. I shot two more .5" groups and a few not as good. I was in a hurry tonight as I was running out of daylight and wanted to shoot a bunch of groups at 100, 200 and 300 yards. I did not let the barrel cool between groups until the mirage was too much. And then I only let it cool till I could shoot again. I don't like running a gun that hot and I think my groups overall suffered from this.
At 100 yards accuracy was about the same as the other day. At 200 yards I managed to put 5 shots into a 1.2" group and another group at 1.5". At 300 yards I shot only one group, because the sun was setting. That group measured 2.545". I was not compensating for wind. The wind was not blowing hard, but was constantly changing direction. I will post a photo of the 300 yard group. Overall I am pretty satisfied with this load. I have no doubt if I had more time and had sorted the two groups of Winchester brass (as I did for the first group of brass) it would shoot better. Although I am satisfied. It is shooting sub MOA reliably.
Also I did notice that the Sierra SMK from the two boxes I have do have some variation in bullet base to ogive measurement. These two particular boxes are no where near as consistent as the the Hornady ELDM I have been shooting. The Sierra's vary by about .006" bullet base to ogive. Over all I think that I will buy some Berger and some more Hornady bullets to shoot. I have no problem getting the 140's to 2900 so I may buy some 147 ELDM or the 156 grain Berger or the 142 SMK. Honestly I really think that I prefer the Hornady bullets.
Another possibility is that although this is all Winchester brass collected from their OTM Range ammunition, they do not all have the same headstamp. I did notice that all of the shots that shot higher velocity opening up the spread were stamped "USA 6.5 CM". The others were much more consistent with the results I had a few days ago. Actually the ones stamped "Winchester" were only a few fps different than what I shot the other day. So from now on I know that the two cases are not the same. Even though they are both Winchester cases. From now on I will sort them by stamp.
Aside from that. The load was shooting pretty well. I shot two more .5" groups and a few not as good. I was in a hurry tonight as I was running out of daylight and wanted to shoot a bunch of groups at 100, 200 and 300 yards. I did not let the barrel cool between groups until the mirage was too much. And then I only let it cool till I could shoot again. I don't like running a gun that hot and I think my groups overall suffered from this.
At 100 yards accuracy was about the same as the other day. At 200 yards I managed to put 5 shots into a 1.2" group and another group at 1.5". At 300 yards I shot only one group, because the sun was setting. That group measured 2.545". I was not compensating for wind. The wind was not blowing hard, but was constantly changing direction. I will post a photo of the 300 yard group. Overall I am pretty satisfied with this load. I have no doubt if I had more time and had sorted the two groups of Winchester brass (as I did for the first group of brass) it would shoot better. Although I am satisfied. It is shooting sub MOA reliably.
Also I did notice that the Sierra SMK from the two boxes I have do have some variation in bullet base to ogive measurement. These two particular boxes are no where near as consistent as the the Hornady ELDM I have been shooting. The Sierra's vary by about .006" bullet base to ogive. Over all I think that I will buy some Berger and some more Hornady bullets to shoot. I have no problem getting the 140's to 2900 so I may buy some 147 ELDM or the 156 grain Berger or the 142 SMK. Honestly I really think that I prefer the Hornady bullets.