85-grain handload group was signifi- cantly smaller than the 80-grain factory- load group. While I was well pleased, my acquaintance was simply thrilled. He turned to me and said, “Smallest group I’ve ever fired.” Then we switched to the 100-grain
handload. He chambered a round and fired, for velocity. Out of the corner of my eye, I noted what seemed to be smoke coming from the action, the significance of which did not register instantly, perhaps because I was dis- tracted, thinking about reading, reset- ting, and rescreening the chronograph. I had to wait until he opened the
bolt before I could go forward, to read the chronograph and prepare it for an- other shot. He had trouble opening the bolt. As I watched him attempting to do so, it dawned on me that something was wrong. When he was finally able to pry the bolt handle up, I asked to see the case. The primer was extremely flat. It
showed vivid engravement of bolt-face marks. The case head was covered with smoke. But most telling was the fact that the primer fell out as I examined the case. At that time, I had been handload-
ing for ten years. That was my first ex- perience with a load that was seriously over pressure. It shook me to the core. Not only because I was concerned about what might have happened but, mostly, because I could not figure out how I had messed up and created such an obvi- ously dangerous cartridge! We never fired another shot with
that load. Later, I pulled the bullets from the remaining 19 loads using the 100-grain bullet. I weighed each charge; each of those was correct. This left me wondering if we had somehow created
one round with an overcharge. So, we did some research. Soon
enough we discovered that his (foreign- made) rifle had a far-too-short chamber throat. Hence, despite being of normal overall length, our 100-grain handload rammed the bullet hard into the rifling. Moreover, bore and groove diameters of his barrel were significantly smaller than specification size for the 243 Win- chester cartridge. The shorter 80-grain and 85-grain
loads worked safely because the bullet ogive was not as far forward. Those bullets were well clear of the rifling. With a free run before encountering added resistance, those bullets could easily swage down, as necessary to fit the bore and engrave the rifling, without causing a significant delay of forward movement, which would result in a significant increase in chamber pressure. Because of faulty rifle chambering
and bore characteristics, my 100-grain handload, which almost certainly would have been perfectly safe in any correctly made gun, was unsafe in that particular gun. I later learned that many early 243-chambered guns from that manu- facturer had given exactly the same results when firing certain 100-grain factory loads. So, this potentially dan- gerous situation was not entirely my fault. Likely, even the recommended starting charge would have generated a significantly too-hot handload when fired in that gun. An obvious question, which you
probably should be pondering: “Why didn’t Mic begin with the recommended starting charge?” I can offer these, perhaps poor,
excuses: âBefore this incident, I had never seen any need to be that circumspect
with any handload; âDoing so would have either re-
quired loading more ammunition to test (we were both working on extremely limited budgets); or, âDoing so would have required
two trips to the range (which was in- convenient and more costly of time and money).
These excuses and this example do
call to mind what my friend Bill Falin (former chief ballistician for Accurate Arms) often notes, “A reason exists for the recommended starting charge! Handloaders would be well advised to heed that recommendation.” The pertinent point in this discus-
sion is that this one example demon- strates the following fact: Neither of the following listed approaches guarantees safety of any given load when used in any given gun: âFiring only factory loads; or, âAdhering to middle, or even
starting, charges in published handload- ing data.
Hence, my contention would be
that all shooters should know how to recognize and interpret pressure signs. Particularly, no shooter who is unwilling to learn how to do so has any business handloading or shooting handloads made by others. I can give several similar examples
of loads that did not respond in accor- dance with any reasonable expectation. One of those was created by following the suggestion of one of the eminent ballisticians in the world. He assured me that it would be impossible to seat a certain bullet on enough of a certain propellant in a certain experimental case to generate normal pressure. So, I filled the case, seated a bullet and we went to the ballistics lab, where I chambered
www.varminthunter.org Page 87
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