Help me interpret these results Berger 215/300wm

[AirborneEScouter]

Trying to figure this combo out - h1000, lapua brass, Berger 215s, cci 250s, 26” proof. Using a labradar to track velocities. Rifle seems to like 76.2 best and looks to just need some seating depth testing (started 0.010” off lands). This is the second load in the brass, virgin brass was not as consistent with the ES/STD DEV and second firing has proven to shoot better. Curiously, the second reload is shooting 50-80fps faster with >76 grains of powder. Am I missing anything? Didn’t feel the need to go above 76.6, started getting light pressure signs at 77 in the first firing.

 

[archp625]

How many rounds do you have on the barrel? I assuming not many and your barrel is speeding up. just keep dropping your powder charge to get back to the node you want until your barrel settles down. Normally that happens between 150-200 rounds.

 

[AirborneEScouter]

Was at about 130 prior to this batch, at 160 now. Would you expect pressures/es/velocities to remain inconsistent during break in? Not worried about speeds just trying to find a consistent node

 

[Rifles And More]

Charge to charge 75.8 and 76 has only 9fps difference - if I read that right. There is a flat spot there. Check out 75.9 to verify and if that holds true you have a velocity node where your charge can be .1gn either way and maintain speed.

From there start on seating depth.

Group size is irrelevant at this stage as it will be tuned by seating depth.

 

[J300UM]

76.2-76.6 are all landing very close to the same poi so it appears you have a stable node in that range. I would do a seating depth test 76.4 as long as pressure is acceptable. I’ve found 215s to run well between .020 and .040 off in the 4 300wm that I’ve developed loads for. Velocity increase on the second firing is pretty common. A little more pressure gets utilized expanding short cases to the dimension of your chamber. If you set your die up to bump the shoulder .002, less pressure is going to be utilized expanding the case so you’ll see the difference there in your velocity.

 

[wind gypsy]

Velocity increase on the second firing is pretty common. A little more pressure gets utilized expanding short cases to the dimension of your chamber. If you set your die up to bump the shoulder .002, less pressure is going to be utilized expanding the case so you’ll see the difference there in your velocity.

^ This. Between the second firing of the brass and the round count on the barrel, the speed up sounds normal.

Nice shooting OP.

 

[Cahunter805]

Was at about 130 prior to this batch, at 160 now. Would you expect pressures/es/velocities to remain inconsistent during break in? Not worried about speeds just trying to find a consistent node

I’ve found once the barrel settles in and speeds up a little it’s much more consistent after. I would recommend loading 76.4 and testing seating depth now. Once you find your seating depth node if it’s still not shooting to your liking you can fine tune powder a bit more. That said H1000/215s are an awesome combo and seems you well on your way already.

 

[AirborneEScouter]

Thanks for all the positive feedback. I’m meticulous in nature but haven’t had much experience with precision handloads and have always felt like ES/standard deviation are the data points to chase and am just trying to break through all the new (the new experience, the new barrel, the new reloading components, etc etc). Has been hard not to lose sight of the forest for the trees

 

[Cahunter805]

Thanks for all the positive feedback. I’m meticulous in nature but haven’t had much experience with precision handloads and have always felt like ES/standard deviation are the data points to chase and am just trying to break through all the new (the new experience, the new barrel, the new reloading components, etc etc). Has been hard not to lose sight of the forest for the trees

ES/SD is always something to watch but for me anything below 20 is fine. Once you start narrowing down your powder/seating depth try to shoot your test at least 400-600 yards. Pick the powder/seating depth that gives you least vertical and good group. It might not be the load with the lowest ES/SD either. You can then fine tune that combo also and test. It’s a rabbit hole man!

 

[J300UM]

ES/SD are certainly important but at the end of the day, the target doesn’t lie. You’re well on your way to the level of precision you’re after. It’s already lookin pretty darn good

 

[Harvey_NW]

I see a lot of potential for both 75.8 and 76.4/6. You can see the POI shift once you get above 76gr indicating a harmonic change, so either ride the edge of pressure with the higher charge or just safely work with 75.8. If it were me, I'd load 20 or so at 75.8 load specs and go see how it shoots at some distance and finish breaking in the barrel and watch the chrono to see if it stabilizes. Maybe flirt with seating depth and .1gr increments above and below and I bet you'll land on an ace load.

Side note, if all your testing is at .010" off the lands I would bet you can load 77gr without pressure if you test .020" or .030" off, if you really like that higher velocity. *Work up to it though.

 

[EdP]

ES and SD are important because poor ES and SD won't yield good groups. However, group size is the goal and you should keep focus on that. I find that my best ES and SD don't always give the best groups. They will be close but not necessarily the best. Barrel harmonic effects don't show on the chronograph.