How to interpret my data. Or am I overthinking it?

[Colterw]

I know I should trust my equipment but I'm having a few doubts. I'm using a MagnetoSpeed Sporter for measuring velocity. With it being 99.5% to 99.9% accurate, at 3,00 FPS that could be a margin of error of 15 FPS. On top of that, with a few of my shots, the chrono slid a bit on my barrel which I'm sure threw my data off a bit. I'm also using the cheap electric scale that Hornady provided with the lock and load kit. I'm measuring every powder charge and zeroing the scale after every time. Sometimes it returns to zero when I replace the pan, sometimes its -.2 to +.2 GN off when I put the pan back.

Now for the numbers.

R700 in 300 Win Mag
Federal GM 215M primer
Hornady 200 grain ELD-X
Hodgdon H1,000
.005 jump

I believe I have found a flat spot in my load from 75.1 to 75.5 grains of powder if I can throw out 2 data points of 7.
75.1 2879
75.1 2837
75.2 2886
75.3 2847
75.3 2881
75.4 2884
75.5 2880

If I can invalidate the slowest two loads, that would give me a ES of 7.

Can I trust the powder scale and the chrono?

Am I anywhere close to consistency?

 

[Cahunter805]

What does the target look like?

 

[Colterw]

What does the target look like?

Grouping was okay but I was mainly looking for velocity and not trying for accuracy. All were in about a 2" group.

 

[WKR]

I wouldn't trust that scale

 

[sndmn11]

I know I should trust my equipment but I'm having a few doubts. I'm using a MagnetoSpeed Sporter for measuring velocity. With it being 99.5% to 99.9% accurate, at 3,00 FPS that could be a margin of error of 15 FPS. On top of that, with a few of my shots, the chrono slid a bit on my barrel which I'm sure threw my data off a bit. I'm also using the cheap electric scale that Hornady provided with the lock and load kit. I'm measuring every powder charge and zeroing the scale after every time. Sometimes it returns to zero when I replace the pan, sometimes its -.2 to +.2 GN off when I put the pan back.

Now for the numbers.

R700 in 300 Win Mag
Federal GM 215M primer
Hornady 200 grain ELD-X
Hodgdon H1,000
.005 jump

I believe I have found a flat spot in my load from 75.1 to 75.5 grains of powder if I can throw out 2 data points of 7.
75.1 2879
75.1 2837
75.2 2886
75.3 2847
75.3 2881
75.4 2884
75.5 2880

If I can invalidate the slowest two loads, that would give me a ES of 7.

Can I trust the powder scale and the chrono?

Am I anywhere close to consistency?

What shots did you throw out?

 

[Marble]

I know I should trust my equipment but I'm having a few doubts. I'm using a MagnetoSpeed Sporter for measuring velocity. With it being 99.5% to 99.9% accurate, at 3,00 FPS that could be a margin of error of 15 FPS. On top of that, with a few of my shots, the chrono slid a bit on my barrel which I'm sure threw my data off a bit. I'm also using the cheap electric scale that Hornady provided with the lock and load kit. I'm measuring every powder charge and zeroing the scale after every time. Sometimes it returns to zero when I replace the pan, sometimes its -.2 to +.2 GN off when I put the pan back.

Now for the numbers.

R700 in 300 Win Mag
Federal GM 215M primer
Hornady 200 grain ELD-X
Hodgdon H1,000
.005 jump

I believe I have found a flat spot in my load from 75.1 to 75.5 grains of powder if I can throw out 2 data points of 7.
75.1 2879
75.1 2837
75.2 2886
75.3 2847
75.3 2881
75.4 2884
75.5 2880

If I can invalidate the slowest two loads, that would give me a ES of 7.

Can I trust the powder scale and the chrono?

Am I anywhere close to consistency?

As far as your scale accuracy goes, I'm not familiar with that particular scale. I use the RCBS digital scale. I can tell you I will have issues with zeroing and correct charges if there is any air blowing across the scale. In the summertime I open the doors of the shop and let a breeze roll through. I have to put the cover over the powder. Otherwise the scale struggles to maintain zero.

I would redo that load again and see what happens. Maybe do other nodes .1 apart.

But shoot for accuracy. It is after all what your goal is.

Sent from my SM-G986U using Tapatalk

 

[Wrench]

I'd load up a few groups at 75.3 and .5. Shoot a group and see what it does. If after 2 shots it opened, I'd stop and go deeper for the next try.

Often low spreads with ho hum accuracy can come around with seating depth. Think charge weights control the burn efficiency and depth plays the harmonics. They can affect each other at some points due to velocity change from the depth, but not typically in 10thou or so.

 

[Colterw]

What shots did you throw out?

I'd be ignoring the two slowest of those 7. The 2837 and the 2847.

 

[sndmn11]

I'd be ignoring the two slowest of those 7. The 2837 and the 2847.

Haha I figured there were others that you left out.

I'd do as @Wrench says and load 75.3 for a 10shot group +3to5 for velocity capture.

I'd also load up in .5 or .3 or .2 grain increments, whatever you are comfy with, above what you have until you see a pressure sign...if you haven't already. The hodgon site has 77gr for their max.

 

[Slugz]

Scale.
Use a scale that measures a kernal of powder.
Eye opening experience for me when I compare the same 55gr drop of H4831SC on my RCBS scale vs my new FX120I.
RCBS only goes to the tenth and required sometimes 3 to 5 kernals to make it go to the next digit.

Compare to my FX120I .02 accuracy and can detect a half a kernal.

Now you gotta balance hunting shooting vs PRS shooting to get what ya want out of your handload.

I think there are other scales out there also like the FX120I with a higher accuracy.

Ive found my chrono ( same as yours) is very accurate when I do everything consistently and correctly. All errors I found was human (me) induced

 

[Colterw]

I've loaded up another batch using an old Lyman M5 balance scale instead of the electric scale in .1 grain increments from 75.1 to 75.5. I should have been using this scale all along. It takes longer but is far more accurate, no re-zeroing and accurate to the individual powder grain. Now to get out and shoot again.

 

[Colterw]

Haha I figured there were others that you left out.

I'd do as @Wrench says and load 75.3 for a 10shot group +3to5 for velocity capture.

I'd also load up in .5 or .3 or .2 grain increments, whatever you are comfy with, above what you have until you see a pressure sign...if you haven't already. The hodgon site has 77gr for their max.

I've only been up to 76.4 so far with the HSM cases I have. AT 76.4 powder is into the case neck. Not sure I could fit any more powder with what I'm using.

No sticky bolt yet but the primer is starting to fire form to the firing pin hole. I'll try get a picture to explain it a little better.

 

[packer58]

Beam type scales are hard to beat for accuracy...........but are slow...

 

[sndmn11]

I've only been up to 76.4 so far with the HSM cases I have. AT 76.4 powder is into the case neck. Not sure I could fit any more powder with what I'm using.

No sticky bolt yet but the primer is starting to fire form to the firing pin hole. I'll try get a picture to explain it a little better.

No picture needed, it's your comfort level that matters. If you are happy with the velocity you have above, I'd just load some up and go shoot.

 

[Wrench]

I used to chase numbers....now I would loose 100fps and keep tight pockets.