6.5CM over a Oehler Chronograph ES 0015/SD 0005

[SONIC SAAMI]

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I have the opportunity today too pass some rounds over a Oehler chronograph. (Thank You 308 Sako)

10 round string
11x fired cases
Hand loaded 6.5 Creedmoor loaded @factory specifications.
FPS 2703 to 2718 for 10 rounds with a Extreme Spread of 0015 SD of 0005
Shot out of a DPMS LR 6.5 Creedmoor

I've never had a 10 shot string with a SD under 6 FPS thought it was pretty good.

 

[Jer]

Re: Shooting over a Oehler Chronograph

Wow, 5 is stellar. What is the length of the barrel you're shooting these out of? What was the grain of the projectiles you used? Is that a typo or are you really using 11x fired cases?

 

[SONIC SAAMI]

Re: Shooting over a Oehler Chronograph

Thats not a typo.
The brass has 11 firings on it.
10x out of a bolt gun.
1x out of the DPMS LR
I have had to trim it twice.
Trimming off about .004 each time
Loaded to the factory Hornady sepc of 41.5g of 4350 pushing a 140 A-X.

 

[pjparker]

Re: Shooting over a Oehler Chronograph

Whatever you are doing, keep doing it !!! SD of 5 is exceptional.

Paul

 

[k2peaker]

Re: Shooting over a Oehler Chronograph

That's very impressive. I'm happy if I approach single digits for SD, not ES.

 

[SONIC SAAMI]

Re: Shooting over a Oehler Chronograph

The only thing I have changed in my brass prep is I now use the stainless media/wet rotary method of case cleaning.
I got a wet rotary tumbler given to me and picked up 5LB of S/S media off a vendor here on the hide.
This cleans all the carbon from the inside of the cases

A set of check weighs is needed.
After zeroing the scale if you should happen to bump it in a way that moves the scale it should be re zeroed again.
Every time the scale gets bump it will be off .1 to .2 grains from zero.

Having the scale mounted up at eye level as also a good idea.
This way you can get a good read on the two intersecting hash marks.

Checking the pan holder for kernels of powder that have fallen out of the trickler when the pan is off also helps.

As of now I don't separate my cases by weight.
Doing so may improve on today's results

Might also try upping the neck tension from .002 to .003
Be sure and make only one change at a time and then test.

A lot credit must be given to the 6.5CM round.
It was designed from the start with the case,bullet and powder all working together.
The Jerry Stiller built rifle shot 1/2MOA and better right out of the box with the DPMS rifle not far behind.
Thanks for the kind words and good luck to all......DavidD