Load development with a newer barrel still speeding up?

MDof2

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Is there a thought process or rule of thumb about working up a load with a newer barrel (100ish rounds) that is still showing signs of speeding up? From what I'm reading on this barrel (Howa) it may continue to do so for another 100 or so rounds.

Bad idea to work up a load or two before it flattens out or safe to do so without much worry of the load going away once the barrel settles down?

Appreciate any input from those who have run down this road before.
 
Not sure, but I would think a load workup now would still give you an idea of what powder and bullet will work well, you may just have to adjust the charge level later.
 
I think so too, but have never come across this scenario. Velocity will change POI, but not pressure, no? So developing to a pressure [velocity] node (think: Satterlee method) with a chrono looking at velocity versus a Newberry OCW method or ladder type test is what got me wondering about it. You'll obviously still see the velocity flat spots as you increase powder, but don't know if that would or wouldn't play well with a new barrel still coming up to speed.
Chummed the water over at THR as well. New territory for me.
 
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Velocity and pressure and how they are related is an interesting study. Don’t know about your scenario, but I will relate something interesting I discovered.

When I was doing a lot of load workups in 45acp (32 different powders to date) I noticed something interesting. For different weight bullets, where there were overlaps in the charge range, I noticed that for a given charge the heavier bullet was faster. Seemed counter intuitive at first, but made sense when you realize the heavier bullet will cause higher pressure. Some of this is due to the weight, but the heavier bullet will also leave less case volume, so I don’t know which has more effect.

In your situation, I have no idea what is causing more velocity. Perhaps the barrel is smoothing out and allowing a better gas seal around the bullet. This should not cause the peak pressure to go up, but the total area under the pressure curve would increase and give more velocity. Who knows. This is way outside my realm of knowledge.
 
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