Funny numbers?

[kfd518]

So I previously worked up a 300 win mag for load with ramshot hunter pushing 180 AB with Winchester brass and cci 34's to 3050 on average with 70.5 gr. I know this powder is between 4350 and 4831 in burn rate. While developing that load it increased as expected with charge increases.

Working with same components and changing to H1000 from 78.5-80.5 gr I got the following numbers,

78.5 3037, 2901, 2879 2866

79 2867, 2895, 2880, 2862, 2879

79.5 2914, 2884, 2879, 2888, 2889

80 2900, 2896, 2909, 2892, 2888

80.5 2977, 2975, 2983, 2986, 2962

Even ignoring those at the ES limits The rate of rise seems inconsequential and weird until it his 80.5
All cases were sized 0.002" bump. And increased by the same amount after firing. All ogives were seated within 0.001 of each other and verified prior to firing.

Does anyone have any thoughts concerning the close to static velocity through 1.5 hrs charge weight? Is this just a node? Didn't have anything like this with hunter powder and have never seen something like these numbers before.

 

[Dmagna]

What cartridge is this for? 300 win mag?

 

[kfd518]

Sorry, yes 300winmag

 

[Dmagna]

You need to keep going until you hit pressure. You should be around 3100 FPS.

 

[Bob Wright]

What chambering? It looks like a 7mm or 30 cal mag?
I see the same patterns with H4831SC where velocity does picks up at increasing powder weight, a flat spot, then a big jump in velocity. It's done that in my 7RM and a 30-06 I'm testing loads for.
I see a node at 79.5 to 80 gr.
You might not be happy at that speed but that points to another powder if you want to push toward 3000. If you're happy, load in that 2900 range and confirm.

 

[kfd518]

Seeing as how the 80.5 gr numbers are what nosler show for their 77 gr numbers I'm going to see where the last half grain puts me. I also need to double check my numbers for case capacity and compare them to nosler data.
There are no pressure signs as of yet. Primers are perfectly rounded!
Depending on what I get for water capacity I may go further but it's pretty compressed already.

 

[QuietTexan]

Barrel length? Both your actual, and the assumed in the load data.

If you keep pushing and get at least another full grain of powder into the case before traditional pressure signs, you might have found a stable spot.

How far are you shooting for? ES and SD don't matter more than what the target shows, if these are grouping where you need them to then forget the numbers.

 

[Bob Wright]

Seeing as how the 80.5 gr numbers are what nosler show for their 77 gr numbers I'm going to see where the last half grain puts me. I also need to double check my numbers for case capacity and compare them to nosler data.
There are no pressure signs as of yet. Primers are perfectly rounded!
Depending on what I get for water capacity I may go further but it's pretty compressed already.

Be careful. I love Hodgdon powders but chasing a speed number I found good ballistically, I started seeing random ejector marks and primer pockets failing. No other signs of pressure. Maybe 20% of my loads.
So, measuring brass at the base (.200 line) before and after and checking primer pockets would be advised. Every gun is different. You're already "pretty compressed".

 

[RegionRat]

Depending on what I get for water capacity I may go further but it's pretty compressed already.

Compression is important too.

Taken too far, you introduce additional risks of issues like seating depth changes and large runout due to the bullet base being pressed by the powder column.

It is nice when our best performance lines up with a powder at exactly 100% case fill, but it doesn't always happen.

 

[kfd518]

As of yet no bullets have pushed from final seated position.
My Barrel length=24"
load data assumed barrel length= 24"
Fire case capacity 92.4 x3, 92.5 x2
Load data assumed 82.3
Difference comes out to 0.6 CC
My coal 3.362
Data speced 3.330

I'm going to try using a drop tube to see if I can get it settled in any better, load shows to be compressed from nosler and does from the point I started my load at to begin with.
Between this and measuring CHE I will proceed cautiously and see if I can get anywhere near their velocity with accuracy still.

 

[kfd518]

One more quick question concerning compressed loads 80.5 is coming up about to the shoulder in the case with these bullets.
I have messed mostly with ball powders and done very little compressed loading. In those that have loaded this cartridge/ powder combo what would you consider highly compressed?

 

[Taylorbok]

fill % is going to depend how deep you have that bullet seated into the case. I usually seat them so boat tail junction is above the neck/shoulder junction so there's some extra room there.

Quick load can calculate it. I just fill it with powder until its up to neck/ shoulder junction weigh that and then subtract a couple grains to estimate 100% fill.

Once the powder starts crunching it's not like you are going to be able to jam in a bunch more powder. I don't normally run compressed loads but I've fireformed with some less than ideal powder using compressed loads.