My reloading experience

[jaybigboy34]

Ok, let me know if this happens to you guys sometimes like it does me.

I did an 8 shot velocity test looking for consistent velocities with my magnetospeed v3 for load development.

The following numbers is what I got: 82gr 2931fps
82.2gr 2957fps
82.4gr 2964fps
82.6gr 2974fps
82.8gr 2976fps
83gr 2986fps
83.2gr 2987fps
83.4gr 2986fps

So as you can see, there is a consistent velocity node from 82.6gr to 82.8gr and also from 83gr to 83.4 gr. So I decided to load up 5 rounds of 83.1gr and see what I got.

My results were not good. I had an average velocity of 2940fps and my ES was 38. I shot five shots at 575 yards and it did group well giving me a .46moa group.

My question is do you all run into these same problems? I can't figure out why my avg velocity went from 2986fps to 2940fps when I used the same brass, same lot of powder, same primers, same lot of bullets. Also the temperature was the same as I shot it just a few hours after the initial load test. The barrel only has 120 rounds down it as well.

Do you all think something could be wrong with my chronograph?

thanks

 

[Olen_4504]

i doubt it's your chronograph.

in your 8 shot load test - how many rounds per charge weight did you do?

you made sure you kept everything consistent and the same when loading up that 83.1g charge?

did you clean the barrel between the 8-shot test and the 83.1g group?

 

[jaybigboy34]

I only did 1 round per charge.
Yes, everything was consistent.
no, I didn't clean the barrel

 

[Olen_4504]

I only did 1 round per charge.
Yes, everything was consistent.
no, I didn't clean the barrel

I don’t know your experience with reloading. And I’m fairly new myself, and I do get the theory behind the type of charge test you did.

However.

Are you certain in your reloading technique that you are producing consistent enough ammo to be able to do a 1 shot test like that?

Maybe if you shot 5 shots per charge you would have noticed all of your groups had high extreme spreads ? And that would mean probably your reloading process needs work.

This might not be the case but just by going off what information I have it’s possible.

 

[padom]

This is why OCW and Ladder are the go to proven methods of finding your optimal charge weight.

While I do shoot everything over a Labradar I always find the center of a node based off consistent points or impact....never has let me down and always produces single digit SD's. Group size means nothing to me during this process..that's what a seating depth test is for after finding the center of the node

 

[CanSniper]

What cal? Is it a new barrel, or recently cleaned?

 

[jaybigboy34]

What cal? Is it a new barrel, or recently cleaned?

300 norma mag only 120 rounds down it.

 

[CanSniper]

Barrel may be braking in, picking up some speed still.

 

[jaybigboy34]

Barrel may be braking in, picking up some speed still.

Velocity went down, not up.

 

[Foul Mike]

With 120 rounds down, what is your barrel break in procedure?
How are the patches between first shot and now? You have cleaned it, right?

 

[_Raining]

https://www.autotrickler.com/blog/thinking-statistically
https://www.autotrickler.com/blog/practical-statistics-for-shooters

 

[CanSniper]

Velocity went down, not up.

Haha, yep good point. Disregard.

 

[spife7980]

Velocity went down, not up.

Is it once fired vs new brass? Formed larger to your chamber volumes are higher (pressure lower) than the tight small virgin brass. Less pressure is less velocity. As has been mentioned above by our esteemed associates. You need way more than one shot to tell anything.

 

[jaybigboy34]

Is it once fired vs new brass? Formed larger to your chamber volumes are higher (pressure lower) than the tight small virgin brass. Less pressure is less velocity. As has been mentioned above by our esteemed associates. You need way more than one shot to tell anything.

I'm using one fired brass.

 

[crunchy]

Seating depth would be my only guess as to why velocity may have dropped. But a guess at this point. Try repeating the process again. Might find out what changed.