added a charge of 26 grains of Hodgdon HS-6 pistol powder, and on top of that added some Cream of Wheat up to the shoulder and topped it off with a dab of Crisco to seal it all in. Using this recipe, we ended up with 260 Reming- ton Ackley Improved brass 95 percent formed. We then resized the cases using a Redding 260 Ackley die and trimmed our cases to five thousandths shy of the chamber length. After trimming, we checked the case volumes of each case
using the H20 method and separated all the cases of the same volume to ensure the utmost uniformity and accuracy. The BenefiTs of Ackley improving Not all Ackley cases are created
equal. Some cartridges benefit greatly from improving the case, like the 30- 30 Winchester or the 250 Savage. With other cartridges the gain is so little it’s sometimes not even worth messing with. The 260 Remington is a cartridge that falls somewhere in between and most shooters never bother with it, partly because a 264 caliber has never really caught on here in the States (which I will never understand), but partly because it’s one of those car- tridges that doesn’t have a large gain over the standard version. Gain, how- ever, is all in the eyes of the builder, and what I wanted out of this cartridge was to shoot a 140-grain Berger bullet ac- curately at long range. A standard 260 Remington case has a case volume of
52.1 grains of H20. The Ackley version has a gain of 2.6 grains in case capacity, weighing 54.7 grains of H20, giving us a
5 percent increase in case capacity – and that 5 percent is all I need. Another benefit to Ackley im-
proving is efficiency. During my load development I found that I was achiev- ing much higher velocities without using more powder. For example, the max load for a standard 260 Remington shooting a 140-grain bullet using Hodg- don Varget powder is 37.0 grains. Ac- cording to the Sierra Reloading Manual, this load should achieve 2,600 fps. Us- ing the Same 37.0 grains of Varget out of my Ackley case produces a velocity of 2,979 fps. That’s a 13% increase in veloc- ity over the standard cartridge. That’s quite an improvement and well worth the time and work needed to Ackley Improve this wonderful cartridge. loAd developmenT And rAnge reporT
The initial barrel break-in process
went quite smoothly and rather quickly with this particular rifle. I took the time to zero my rifle during the break-in process so I wouldn’t need to waste costly components to get on paper when it was time to start testing loads. Before I got too crazy testing various powder and bullet combinations, I poked around the World Wide Web looking for other shooters’ pet loads and recipes for this particular cartridge. I found two loads that kept popping up for a 140-grain bullet. One was using 46- 47.5 grains of Hodgdon 4831SC and the other 44-47 grains of Ramshot Hunter. I happened to have a keg of Ramshot Hunter, also donated by Trent, and
a couple of pounds of H4831SC, so I loaded about 10 rounds of each. Since I was using Military Match cases I backed off the powder charge a bit to ensure I wouldn’t have a hot load. I loaded 10 rounds with 43 grains of Ramshot Hunter and 10 rounds with 43 grains of H4831SC. I seated a 140-grain Hornady A-Max at 0.0200" off the lands on five of them and 0.0300" off the lands on the other five for each load. Surprisingly, the start loads cho-
sen still showed some slight signs of pressure by flattening out the prim- ers on each load. The loads, however, seemed to work pretty well out of my rifle, with both loads producing five- shot groups that could be covered with a nickel at 100 yards. Another interest- ing note is that both loads with the bullets seated 0.0300" from the lands shot much better than the load with the 0.020" seating depth. Just goes to show how much of an impact adjusting the seating depth can affect your load. After my first outing at the range
I was extremely happy with the results. I had just shot two five-shot groups well under an inch at 100 yards and I hadn’t even begun any load develop- ment yet. I knew this rifle was going to be capable of great things – all it needed was a little fine tuning. I went back to the bench and decided to try a few different things. First thing I did was change the bullet. I switched over to a 140-grain Sierra MatchKing. The bullets from the green box have never before let me down and I was hoping
Page 168
Spring 2012
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100 |
Page 101 |
Page 102 |
Page 103 |
Page 104 |
Page 105 |
Page 106 |
Page 107 |
Page 108 |
Page 109 |
Page 110 |
Page 111 |
Page 112 |
Page 113 |
Page 114 |
Page 115 |
Page 116 |
Page 117 |
Page 118 |
Page 119 |
Page 120 |
Page 121 |
Page 122 |
Page 123 |
Page 124 |
Page 125 |
Page 126 |
Page 127 |
Page 128 |
Page 129 |
Page 130 |
Page 131 |
Page 132 |
Page 133 |
Page 134 |
Page 135 |
Page 136 |
Page 137 |
Page 138 |
Page 139 |
Page 140 |
Page 141 |
Page 142 |
Page 143 |
Page 144 |
Page 145 |
Page 146 |
Page 147 |
Page 148 |
Page 149 |
Page 150 |
Page 151 |
Page 152 |
Page 153 |
Page 154 |
Page 155 |
Page 156 |
Page 157 |
Page 158 |
Page 159 |
Page 160 |
Page 161 |
Page 162 |
Page 163 |
Page 164 |
Page 165 |
Page 166 |
Page 167 |
Page 168 |
Page 169 |
Page 170 |
Page 171 |
Page 172 |
Page 173 |
Page 174 |
Page 175 |
Page 176 |
Page 177 |
Page 178 |
Page 179 |
Page 180 |
Page 181 |
Page 182 |
Page 183 |
Page 184 |
Page 185 |
Page 186 |
Page 187 |
Page 188 |
Page 189 |
Page 190 |
Page 191 |
Page 192 |
Page 193 |
Page 194 |
Page 195 |
Page 196 |
Page 197 |
Page 198 |
Page 199 |
Page 200 |
Page 201 |
Page 202 |
Page 203 |
Page 204 |
Page 205 |
Page 206 |
Page 207 |
Page 208 |
Page 209 |
Page 210 |
Page 211 |
Page 212