Ok lease help me and make sense of this please

[Utectok]

I'd hazard a guess that this is erratic ignition, which often happens with magnum primers in some cartridges. May I ask what cartridge this is?

Also, is this a fairly new barrel?

No magnum primers it’s a swede with about 1000 rounds up the tube

 

[Mungo]

So @Mungo I did add the all up and the sd from 58 shots was 37.25 and the es 135.3
Average 3091
In a weird sort of way I sort think ok I’m sure most loads drift northward with spread if you test them with enough data just like most “.5moa” rifles wouldn’t put 100 shot inside 1/2 and inch

SD increases with sample size.

It’s a variable load, but not excessively so.

 

[hendrix's rifle]

I'm not sure if you've already posted it - what is your charge weight? Are you up there at the top end or a bit lower down?

Are you certain all rounds were out the way of the sun? Any dwell time leaving rounds in a hot chamber?
I'm still tempted to say temp sensitivity because if all is equal, rounds the same temp and everything else it would appear you have quite a large SD/ES. Did you load them all up at the same time or in batches?

 

[Utectok]

I'm not sure if you've already posted it - what is your charge weight? Are you up there at the top end or a bit lower down?

Are you certain all rounds were out the way of the sun? Any dwell time leaving rounds in a hot chamber?
I'm still tempted to say temp sensitivity because if all is equal, rounds the same temp and everything else it would appear you have quite a large SD/ES. Did you load them all up at the same time or in batches?

This is all good sense I’m quite possibly to blame I reload carefully but mistakes do happen as I loaded theses then unloaded them and adjusted the load which wasn’t the best idea

 

[Utectok]

This is all good sense I’m quite possibly to blame I reload carefully but mistakes do happen as I loaded theses then unloaded them and adjusted the load which wasn’t the best idea

I mean I was at a high pressure and dropped down a grain. I was careful about the sun but ??? The weird one was the last 22 shots fired were all pretty good so it could be something I’ve done ? I’ll test some more at the weekend.
Somebody told me I was at the edge of a node but to be honest I’m not at all sure “Nodes” exist and it’s more likely they are more low sample size nonsense along with tuning your rifle with seating depth and barrel tuners!! Duck for cover heretic that I am lol

 

[Zio65]

Forgive my ignorance, what do you mean by ES?

 

[Utectok]

Forgive my ignorance, what do you mean by ES?

Extreme spread

 

[Mungo]

I mean I was at a high pressure and dropped down a grain. I was careful about the sun but ??? The weird one was the last 22 shots fired were all pretty good so it could be something I’ve done ? I’ll test some more at the weekend.
Somebody told me I was at the edge of a node but to be honest I’m not at all sure “Nodes” exist and it’s more likely they are more low sample size nonsense along with tuning your rifle with seating depth and barrel tuners!! Duck for cover heretic that I am lol

Nodes might exist. I doubt many people shoot enough at each charge level to detect them.

I can very easily recreate the illusion of a node with randomly simulated data.

 

[bbell]

Have you shot it at distance? Not sure what bullet your using but I put your highest velocity and lowest velocity in a ballistic calculator with a BC of .390 and it was about an 8” difference at 600yds. 2.5” difference at 400yds. High or lower BC will obviously change that. All that to say it’s probably fine unless you’re really trying to reach out there.

I have fun fine tuning stuff but sometimes it’s more fun to just shoot and not sweat the small stuff.

 

[Utectok]

Have you shot it at distance? Not sure what bullet your using but I put your highest velocity and lowest velocity in a ballistic calculator with a BC of .390 and it was about an 8” difference at 600yds. 2.5” difference at 400yds. High or lower BC will obviously change that. All that to say it’s probably fine unless you’re really trying to reach out there.

I have fun fine tuning stuff but sometimes it’s more fun to just shoot and not sweat the small stuff.

I think I’ve got about 15cm at 500m which is perfectly fine for hunting under 350m but like you I’m keen to tinker and get the sd down a bit… watch this space as they say

 

[Utectok]

I think I’ve got about 15cm at 500m which is perfectly fine for hunting under 350m but like you I’m keen to tinker and get the sd down a bit… watch this space as they say

4cm at 350m

 

[Mungo]

4cm at 350m

So substantially less than 1MOA. In fact, rather less than 0.5MOA. You’d need a very accurate gun, perfect conditions and be on top form to notice the difference.

 

[Utectok]

Mm I sort of wonder if the garmin might have been picking up a neighbors shots?? I did see one get picked up and he was close and running similar velocities
Further test this week not too bad

 

[LuckyEddie]

Ummm...you understand that 3gr variance between ammunition cases, often times is just the difference in the extractor cut into the case head, right? Then factor in that bullets can vary quite a bit as well in weight.

All these stacking tolerances can easily give a false impression when weighing loaded ammunition. Which is why most people don't bother doing that.

I spoke to a person that helped the Americans that shot in the Palma Cup back in the 90s and it does make a difference.
To such an extent that when the Americans learned of what to do, they offered free beer to any shooter that had electronic scales to help them weigh the full rounds before the match as this was arranged at short notice.
From some 30k+ rounds the top and bottom quartile were discarded and the rest shot.
Feel free to check this out.

@Utectok don’t bother with h2o just the fully loaded dry round is good enough.
You’ve weighed the powder, the bullets are manufactured to a good tolerance and the outside of the cartridge has to be made to fairly strict tolerance.
The light loads will shoot low and have a slower velocity to the heavier rounds which will shoot high.