Come, let us read tea leaves...

[Orcon]

So after a year or so of reloading, and having worked out most of the basics without grievously injuring my self or others I have finally succumb to the accuracy bug. I had heard of various forms of OCW testing and ladder testing. I settled on the Dan Newberry method because it seemed the most straight forward and most commonly known by those I shoot with. The first shot group is a combination of sight in/ foulers and post test confirmation with a hunting load of 165 gr SST and Varget, ten rounds in total. From there we go to 3 shot groups looking for center mass similarities across several groups, not necessarily smallest group size.

Distance 105 metres (115 yards)

The rifle used in this test is a .308 WIN Remington 700 SPS "tactical" 20" bull bbl and crappy hogue stock on a Harris bi-pod. It is nothing fancy.

The load materials used are:
Hornady match brass
175 gr Nosler Custom Comp (courtesy RMR Bullets)
Hodgdon Varget powder
WLR primers
Seated at 2.86 COAL

Powder charge for shot groups left to right:
(165gr SST hunting load for control/sighting 10 rounds total)
45.3gr
45.0 gr
44.7 gr
44.4 gr
44.1gr
43.8gr
43.5gr
43.2gr

I am going to go with the two in the middle that are high and slightly left of center, 44.4 and 44.1 grains.


My results were some what surprising to me, I expected more rise from higher powder charges. I think I might try this same test again at 200 or maybe 300 metres. What do you think?

 

[Reloadron]

Generally I like a minimum of 5 shot groups.
Unless I missed it I don't see the caliber loaded? I see powder charges and the bullet used. I just don't figure 3 shot groups tell you very much. Just my thinking.

Ron

 

[Orcon]

Sorry, OP updated .308 WIN


This isn't about smallest group, it's about finding a charge weight. In terms of group size, over time I'd expect them to grow to the size of the large control group on the far left of the target.

 

[AnselHazen]

I like how you shoot one round from each charge group at a time at it's respective target, then go back and do it again, twice more. Seems like a good way to keep the test more focused on how well the round does and not how well you could shoot a group.

 

[SSN Vet]

Your load is getting nicely refined... but it looks like it's time to adjust your scope elevation a couple clicks

 

[Blue68f100]

If you only look at Vertical spread the 2nd & 3rd target from the right appears to be the smallest. I would now test around those charge area trying to find which gives the smallest Vertical spread. Then go play with over all length to tighten the group.

 

[Robert101]

I'm not a precision shooter, but I too like the groups on the right side of the picture. I tend to shoot 5 shot groups as I feel the propensity to get "lucky" sometimes and my three shot groups may not represent the probability of the charge/load. So I guess I'm stating that I don't trust my repeatability. Lastly, good shooting.

 

[Gtscotty]

OCW tests generally call for 3 shot groups to start off with. The OP can check his chosen loads later with larger groups.

As long as you are getting acceptable velocities, I would probably pick the group above the sticky 4th from the ends. The groups on either side have very close centers. If I were doing the workup, I'd take that charge weight and load up 5 rounds at different OAL's and see what I had. This is all relative to the bottom picture, i can't see the top.