goodgrouper
tryingtobeabettergrouper
For anyone interested, I ran another test on XBR today. It was very interesting--at least if you're a ballistic nerd like me. If not, don't bore yourself with the remainder of this post.
I took my leftover ammo that I loaded on Sunday in the deluge at the Cactus and fired it for group and chronographed it too. It was loaded at 55 degrees and 100% humidity at 1630 foot elevation with 53 clicks of XBR. It was fired today at 65 degrees with 35% humidity at 4880 foot elevation. It clocked 3352 fps with a deviation of 9 fps. It shot very well for the windy conditions at the mouth of a canyon and I guessed it at a mid "one". I would say that if the conditions had been more civil, it would have shot every bit as small as it did in Phoenix.
So, with the same bullets, barrel, powder, primers, thrower, and setting of 53 clicks, I loaded up more ammo and fired it immediately after shooting the Cactus ammo. It clocked 3338 with a deviation of 2 fps. The group was still good given the conditions. It was probably a high "one".
Then I set up my Chargemaster and weighed what 53 clicks was throwing. In Phoenix, it was throwing 30.9 to 31.1 grains. Today, it threw 31.0 to 31.1.
Then I dropped down to 51.5 clicks and shot it. It gave a nice round group that seemed a little less wind sensitive and was around a mid "one". It clocked 3240 fps with a deviation of 11 fps.
Then for kicks, I took a different lot of XBR and threw 51.5 clicks with it and shot it. It was the best group of the day and clocked 3217 fps with a devation of 10 fps. Not too bad for lot to lot consistency with these two lots anyway.
So what does this mean? Well, I'm not sure. Except for the fact that ammo loaded 600 miles away in a totally different climate shot well at home too without much variation in accuracy attained or velocity measured. That being said, a load tuned for the conditions today did shoot better and it happened to be a charge that was backed down quite a bit from what worked in Phoenix on Sunday. But it was warmer today by ten degrees.
I guess it just goes to show that we still need to lug all the reloading equipment around to each match no matter what powder we use!
P.S. I would have brought all my targets home to measure them but they were too messy to bother with. The flys were out pretty thick today and they found some shelter from the wind on my target paper, and well, I couldn't resist!
I took my leftover ammo that I loaded on Sunday in the deluge at the Cactus and fired it for group and chronographed it too. It was loaded at 55 degrees and 100% humidity at 1630 foot elevation with 53 clicks of XBR. It was fired today at 65 degrees with 35% humidity at 4880 foot elevation. It clocked 3352 fps with a deviation of 9 fps. It shot very well for the windy conditions at the mouth of a canyon and I guessed it at a mid "one". I would say that if the conditions had been more civil, it would have shot every bit as small as it did in Phoenix.
So, with the same bullets, barrel, powder, primers, thrower, and setting of 53 clicks, I loaded up more ammo and fired it immediately after shooting the Cactus ammo. It clocked 3338 with a deviation of 2 fps. The group was still good given the conditions. It was probably a high "one".
Then I set up my Chargemaster and weighed what 53 clicks was throwing. In Phoenix, it was throwing 30.9 to 31.1 grains. Today, it threw 31.0 to 31.1.
Then I dropped down to 51.5 clicks and shot it. It gave a nice round group that seemed a little less wind sensitive and was around a mid "one". It clocked 3240 fps with a deviation of 11 fps.
Then for kicks, I took a different lot of XBR and threw 51.5 clicks with it and shot it. It was the best group of the day and clocked 3217 fps with a devation of 10 fps. Not too bad for lot to lot consistency with these two lots anyway.
So what does this mean? Well, I'm not sure. Except for the fact that ammo loaded 600 miles away in a totally different climate shot well at home too without much variation in accuracy attained or velocity measured. That being said, a load tuned for the conditions today did shoot better and it happened to be a charge that was backed down quite a bit from what worked in Phoenix on Sunday. But it was warmer today by ten degrees.
I guess it just goes to show that we still need to lug all the reloading equipment around to each match no matter what powder we use!
P.S. I would have brought all my targets home to measure them but they were too messy to bother with. The flys were out pretty thick today and they found some shelter from the wind on my target paper, and well, I couldn't resist!
I'm liking it.