6.5 creedmoor ocw test

[dirtking]

I did another ocw test. The only thing I changed was from a vortex pst to a nightforce nxs. All loaded with h4350, fed 210m and 140gr amax. Coal was 2.800. We're shot round robin off bipod and rear bag. I had a called flyer on the 42.6 load.
Velocities
41.1- 2672,2693,2710
41.4- 2737,2699,2710
41.7- 2743,2699,2749
42- 2749,2760,2760
42.3- 2795,2760,2772
42.6- 2801,2783,2807
42.9- 2795,2812,2824
43.1-2789,2824,2795




I'm thinking my node is between 42.3-42.9. Anyone else see something different.

 

[Dan Newberry]

If you're sure that was a self inflicted flyer at 42.6, then I'd say you definitely have something at that charge level. See if it repeats, and if so, I'd say you're done.

 

[mkollman74]

Straight from the man himself.

 

[dirtking]

Thanks Dan! I will load up some more at 42.6 and retest. It that was in fact a flyer (pretty sure it was) should i just use that as my ocw or go up to the 42.9 load?

 

[dirtking]

I loaded up 5 rounds each at 42.6 and 42.9 and shot them at 288 yards.

This is the 42.6 load


This is the 42.9 load


Am I just that terrible of a shooter or did I not do a good ocw test?

 

[dworrel]

I had a similar experience in my 6.5 CM work-up

SAC barrel for DTA SRS. I had an obvious node from 42.4-43.0 gr H4350 with CCI-BR2 and 140VLD.

When I stretched it out to 300yds, the groups really opened up. I shot a 500yd group as a last resort and had a 2" 5-shot group with 42.5gr. Called it quits. I have seen several other guys on this site with a similar load.

 

[dirtking]

Thanks dworrel! I am thinking just running with the 42.6 load and get practice.

 

[JGorski]

I loaded up 5 rounds each at 42.6 and 42.9 and shot them at 288 yards.

This is the 42.6 load


This is the 42.9 load


Am I just that terrible of a shooter or did I not do a good ocw test?

Was there any wind with that 42.9 load? Was your rifle loose or tight in the front bag? if the ladder was all good then the wind spread those holes out. You have a mighty fine vertical there

 

[dirtking]

Jgorski, there was no wind. The ocw test was shot off a bipod and rear bag. I also like the vertical in that load!

 

[Fredo0621]

Have you touched your seating depth yet? Mag length limited?

 

[dirtking]

I am running them to the same ocgive length.as the factory match 140brass which shoot well. I am running a manners mini chassis dbm

 

[dirtking]

Ok guys I decide to shoot the same loads again. These were shot at 268 yards.

42.6 - disregard the group at lower right as that was 120gr factory loads.


42.9


The 42.6 load measured 1.3" so close to 1/2moa. Should I know start playing with seating depth or just run with it? Thanks for everyone's help!

 

[devildogandboy]

Was there any wind with that 42.9 load? Was your rifle loose or tight in the front bag? if the ladder was all good then the wind spread those holes out. You have a mighty fine vertical there

myself, I would go with this 42.9 load and play with the length, maybe start moving it out in increments of .010 and see if it doen't pull together. just mho.

 

[VKC]

Look for the group with this least vertical stringing, which is more important than the horizontal unless you are strange barrel harmonics. You may also want to look at annealing your cases and seeing whether it is varying neck tension from hardened brass.

 

[dirtking]

So you guys think I should use the 42.9 and play with seating depth or start over with load development at longer range than 100 yards?

 

[HobbyShooter]

I think you need to decide what kind of a development test you're doing. OCW would have you focus on a string of charges with a similar point of impact, pick one in the middle of that string, and then fine tune group size with seating depth. In which case 42.6, as Dan suggested, is golden (especially at .5 MOA with no seating changes yet).

A ladder test focuses on vertical dispersion, but is shot differently than what you've started here.

I like to shoot, so I'd call 42.6 my winner and start loading up. If you're enjoying the detective work of searching for your rifle's perfect load, you may want to load 42.6 and 42.9 at different seating depths and see which one you end up liking best.

 

[dirtking]

Everyone thanks for the advice. I would rather just be shooting also especially since my supply of h4350 is getting about scary low. Think i will just load up the 42.6 and work on moving out to distance and getting trigger time.

 

[JGorski]

Id seat your bullets no more than .010" off the lands and go shooting. Can you post a pic of your rig with the rear bag and bi-pod?

 

[dirtking]

Only thing different from the pic is it wears a nightforce nxs in nightforce rings.

I will have to double check to see if I can get the 140 amax to 10 thousands off the lands and still fit in the mag.