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Posted: 11/24/2010 1:05:51 PM EDT
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I’m not sure what to make of this test because nothing grouped like other targets I have seen of ladder test.
Rifle – OBR 18” Temp – 30 degrees Wind – 0-5 left to right with gusts of 5-10 (doesn’t really matter for this) Overcast with sleet during second round of firing Lapua brass, Sierra 175 MK, M210 primers, reloader 15 Distance - 300y 1 – 40 2 – 40.5 3 – 41 4 – 41.5 5 – 42 6 – 42.5 7 - 43 I shot 10 rounds to foul the clean barrel waited 2 minutes and then started the test. I fired the first shot, drove to the target, marked it, drove back, and fired the next shot. There was approximately 2 minutes and 15 seconds in between shots and I was consistent in my time. The rifle had a bipod up front and sandbags in the rear and the same point of aim was used every shot. I’m assuming that I have done something wrong and to my untrained ladder test eye it looks like I wasted my time but what do you all think? 1 through 7 first round 1-2 through 7-2 second round. Click here for target |
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Quoted:
1 – 40 2 – 40.5 3 – 41 4 – 41.5 5 – 42 6 – 42.5 7 - 43 I shot 10 rounds to foul the clean barrel waited 2 minutes and then started the test. I fired the first shot, drove to the target, marked it, drove back, and fired the next shot. There was approximately 2 minutes and 15 seconds in between shots and I was consistent in my time. The rifle had a bipod up front and sandbags in the rear and the same point of aim was used every shot. I’m assuming that I have done something wrong and to my untrained ladder test eye it looks like I wasted my time but what do you all think? 1 through 7 first round 1-2 through 7-2 second round. Click here for target The way I understand it, you shoot all those shots and look for a group. To my eye, 4, 5, 5-2 make a nice group. And then 6, 6-2, and 7-2. Since 4-2 and 7 are outside of those groups, I'd look at loading up 10 each of 42gr and 42.5gr. I bet one of those loads is going to group very consistently and you can reset your zero for that load. ETA: Heck, you might even try a batch at 42.3 or so. |
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One shot at each charge weight won't show anything, except maybe if you have an exceptional quarter minute rifle.
Shoot 3 to 5 rounds at each charge weight. Shoot at the same aiming point, one that has good contrast and is well defined and easy to hold with precision. Shoot 3 rounds if the conditions are good and you're confident you can call shots and have good bench technique to save components. Watch the groups climb the target. Groups that collapse and land on top of each other indicate you're in a tuned range. You'll want to revisit a promising load to make sure first indications are correct and hold up over a longer string of shots. One tight group that has larger groups with charges on either side is a trap; this load will fall apart when the ambient conditions change. |
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Quoted:
One tight group that has larger groups with charges on either side is a trap; this load will fall apart when the ambient conditions change. That was why I was thinking 42.3 based off the shots shown on target. 42.0 and 42.5 seemed to stay together pretty well. 42.3 may fall pretty good and the consistency on either side should be good for changing conditions. I'm NOT an expert by any means, but I have done this before. |
Slightly off topic but related. One trick I learn doing this to make things a little easier is to setup a video camera close to the target (not too close  ) and tape the event after the fouling shots. This way, you can concentrate on shooting the ladder and later with the target and video, you can tell which shot is which. Good luck with the ladder.
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| I usually set up multiple targets. Start on target one with load one and move to each target with the corresponding load number. Then go back through the targets in reverse order. Keeps the fouling or barrel heat from favoring one group. So essentially you are working on 5 different groups all at once. Use identical targets and then compare the group location using the grids when you are done. |
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it's very time consuming but i'll mark on the target ahead of time the load i'm shooting. that way if the range is all mine i post them all.
i shoot at a private club and there usually aren't too many people shooting so i can generally post six to eight targets; if i go high and low i can post 12-16. |
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