On Tuesday we grabbed the OBRs in the morning and then traded them out for our personal guns for the afternoon Wind Course. (See photo 3). It’s called the Wind Course for obvious reasons, and your score doesn’t count unless the winds are at least 15 mph sustained. Our scores counted since we had a max wind reading of 37 mph. Your score is determined by getting 2 points for a first round hit on a target and 1 point for a second round hit. There are 15 targets (we only saw 13) located around the top 360 degrees of the hill. Max score is 30. The course record was set by Scott last year and stands at 17. I tied Mr. Beaufort with a whopping 6. I got a point on the 318 meter target, one at 467, one at 632, two at 530 and one at 450. The targets placed at 650 to 800 meters were completely safe. Scared maybe – from close misses – but safe. I wore some very fashionable goggles that kept my eyes from tearing up and getting sandblasted. I carried my gear in an Eberlestock Gunslinger pack (GS05ME) that has a rifle pocket big enough to carry the OBR or my Tak-MAK. It also carried my water, trail mix, rangefinder, Kestrel, notebook, sandbag, goggles and first aid kit. There’s room for more than that but I was trying not to weigh myself down with a hundred pounds of lightweight gear. We left our shooting mats (5 lbs) behind for the same reason, not to mention that the steely eyed death merchants we were with didn’t carry pads so we didn’t want our lacy undies to show. Fortunately, the occasional hit waaay out there took our minds off the rocks we were laying on.
Wednesday was the day we went for The Mile Shot. We started out at some closer range targets before working up to 1609 meters (one mile). We shot at 340, 660, 688, 760 and 794 meters. Then at 1000 meters I held 9 mils and held 3.4 mils into the wind. At 1070 meters we found a 12 inch plate painted black. I hit it with a hold of 10 mils and 2.7 mils into the wind. At 1270 meters I held 14 mils elevation and 4 mils into the wind. Finally it was time to shoot into a different time zone/zip code. I lazed the target twice and got 1610 and 1611 meters. Mr. Beaufort went first, with his 338, shooting 250 grain BTHPs. His elevation ended up being 18.5 mils. By contrast, we asked the OBR shooters what they were holding and they were at 34 mils. After he whacked the steel (12 inch circle over a 16 inch square) a few times, it was my turn with the 260. I came up 13 mils on the elevation dial (I only had 14 mils left on the dial) and then held 8 more mils on the reticle. No joy – no puff of dirt could be seen. Hold 9 mils and let fly. No joy. Hold 10 mils and let fly. Yeah – a puff of dirt marked the impact. From there I was able to adjust for the wind and start hitting on and around the steel. In total, I hit the steel three times with the 260 (witnessed). I connected with holds from 23 to 24 mils and 2 to 4 mils into the wind. The parallax at the bottom of the field of view in the scope was running from the top to the bottom of the target. That plus the changeable wind, plus my belly shooting (dis)abilities, plus the elevation variations due to muzzle velocity variations (about 23? worth of vertical between 2771 and 2789 fps) and I’m amazed that I ever hit anything at that distance. After hitting the target with the 260 I gave the 338 a try. On the tenth shot I rang the steel with one of the 250 grainers. I got back to the hotel and wrote in my notebook, “Good day in Canadian. The wind was 16 mph, which sure beats 37. No grit in my teeth today. I hit the mile target three times with the 260 and once with the 338. I had beef quesadillas and bread pudding for supper and a lady (Dianne) left cookies for us at the hotel.” Pretty friendly locals. Thanks, Dianne.
The ballistic solver that I used was the Kestrel 4500 NV Horus. It combines wind speed, pressure, temperature, etc. with a PDA. You can call up a range card that calculates holds for elevation and windage in 10 yard or greater increments. It’s a really sturdy unit that put up with all the blowing dirt and kept ticking. The battery life is also very good. With the “environment” turned on, the unit constantly updates the meteorological data and changes the range card to account for the changes. You can enter and save a bunch of guns in memory and then pick the one you’re using. I entered 260 Rem, 2775 fps, .60 BC (G1), 140 grain, .264 diameter, 100 meter zero, 2.91? sight height and right hand 1:8 twist barrel. You may have noticed that I said the effective BC was .64 earlier in the article, which is true, but I had to lower it to .60 to agree with the come ups out to a mile. Apparently the transition to subsonic flight made the difference. Or something(?). Hey, if I had all the answers, I’d write a book.
Barrel #3 accuracy results: Getting back to work after I returned from Texas, I installed barrel #3 and shot about one hundred rounds through it – averaging .80 MOA for its three shot groups. The 130 Norma shot a .55? three shot group at .020? off the lands. A follow on five shot group measured .65?. The meplat on that bullet sure is small. The best group with this barrel, a .24?, was with the 142 SMK over 38 grains of Varget, at 2638 fps.
Barrel #4 accuracy results: I fired 120 rounds with an average three shot group size of .81 MOA for all the groups. My best groups include the 140 Berger VLD at .37?, the 140 A-MAX at .35?, the 142 SMK at .29? and the 123 Scenar at .20?.
Barrel #5 accuracy results: Up until this barrel I felt that the performance of the barrels was pretty similar, running .7 to .8 MOA, and I wasn’t expecting #5 to be much different. Then I started shooting this barrel. The second outing I put up a sheet of paper with eight orange dots to record my eight three shot groups. I loaded 39.5 grains of Viht N150 under various seating depths of 139 grain Scenars, 140 grain A-MAX bullets and 142 grain SMKs. I averaged .44? for the eight groups. The best group was .20? with the A-MAX bullets. These were the old style, pre AMP bullets. For the next day’s outing I loaded five rounds of this same load plus some other new loads. Scott hadn’t shot a 260 so he volunteered to do the shooting. I showed him the .20? group and told him that all I needed was nothing less than his absolute best shooting. I was watching through the big Unertl spotting scope as he punched out a .34? five shot group. Yep, that’ll work. I think I’ll hold onto this barrel.
The 140 grain A-MAX is a target bullet, but that didn’t stop me from thumping a block of 10% ballistic gelatin with it at an impact velocity of 2751 fps. The bullet penetrated 13 inches, expanded to .66? and weighed 63 grains. The bullet expansion started immediately – no neck length. I also shot a few other bullets into the ballistic gelatin with the photo and penetration results shown below.