My load test findings "my way"

[Bubb]

Okay got my tikka t3 in 7mmMag loaded four 6 shot ladders in .5+ increments shot them at 200 yards and over my
Chronograph. I wanted to see if one or the other showed better findings? As stated in my other post 20 shot load. I outline my
Process step by step. I'm trying to see if one is better than the other? I did find that as my friend Ken said I pushed and pulled shots, but the numbers read differently. If I where to use just the targets for my finding it would be pretty tough.

As you can see on the H1000 ladder 4-5 are close to 8" vertical.. But when you look at the velocitys those two shot identical speed. That target really would of tripped you up without the chronograph. Her are the numbers

The targets really didn't give me much to go on. But with the numbers I'm going to load in the middle of my circled velocitys to shoot for group. In 32 shots I tried 4 powders, most guys burn that on one OWC test. I'm going to load 68.7 of H1000 that was the best node. And I'll try 70.9 of Retumbo cause it gave best speed. Might even try 65.5 of MRP. I'll shoot 5 shot groups at 200. So in 15 more shots I (should) have something????? Any thoughts on those targets. After this test I'm leaning more towards Kens way just shoot in the dirt for load development the rest can be misleading, at best.

 

[clrems77]

I'm looking forward to your results. I'll be back out to the range next week to finish my 20 shot testing with the seating tests. I'll keep you posted!

 

[Bubb]

Great clrems77 I'm looking forward to seeing how
It worked for you. I'll shoot my top three for group
This weekend. I'll see which one does best. For this
Bullet I gotta stop there. I'm at max mag length. But
If accuracy isn't there I'll try another bullet!

 

[Bubb]

Well the learning curve continues. I shot 4 five shot groups loaded in the node for each powder. What did I get?.. About the same groups as what the ladders looked like?.. My only conclusion is my mag length of 3.290 is too much a jump for the Bergers?.. So I'm going to try a 160 Speer hunting bullet just to see if it's any better? For this test I'm going to pic book max and load 5 ?. Scratching my head alittle on this? I guess you can be in the node, but if the bullet isn't stable still won't group? Any thoughts.

 

[CharlieNC]

Bubb trying to interpret one shot/load over the chrono will not give you any better clarity than reading that same single shot on a target. If you consider the ES, or better yet the SD, for a group of "identical" loads the statistics are such that you need a larger sample size to determine if there really is a real statistical difference between loads. I think you are seeing it is more definitive, and less work in the long-run, to run an OCW type trial in the beginning. I personally use the optimum barrel time (OBT) calculation to identify a narrower load range to focus in with OCW type of shooting approach, and have found the calculated OBT powder charge is within 5% of the actual OCW result.

 

[Bubb]

CharlieNC what are you talking about OBT?. I've never heard or read about it! How do you calculate it? Is will give you a starting point for OWC?

 

[CharlieNC]

Google Chris Long OBT for details. It's a form of barrel harmonics associated with the timing of the shock wave effect on muzzle behavior, instead of vibration. Easy to calculate nodes based on barrel length, then you use Quick Load to calc loads to match the OBT times. I've had good correlation for several calibers, using different powders and bullets. Some days I find the calcs are better than my shooting to find the nodes! I'm thinking about setting up an affordable service to do this someday.

 

[Bubb]

Charlie I don't have quick loads?.. If I measure my Barrel, list components I'll use could you get me pointed in right direction? Very interested in this process. I'm almost 100% sure my main problem was the mag length was too much jump for the Bergers.

 

[CharlieNC]

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