RESULTS! 308 load development dorkulating: OCW test results herein (gigantic unwieldy pic inside)

So I shot an OCW test, sorta to confirm what a ladder test told me. Question is what charge do I load. They all shot pretty good, and some made tiny groups –– all this was at 100 yards. Charge weight - Varget if you care –– is the big number written in marker. Tiny numbers are measured velocities using my F1 chrony. Point of aim was the center dot. Then there's the point of impact offset, which I measured and wrote on each target which if you stare hard you can see on the top right of each bullseye. Here's the embedded pic:



If you can't see the full size pic here's the link: picture

To be clear I'm splitting hairs, but after all this is precision rifle. On the other hand I thought doing this OCW test would make the clouds part and show me the one true load for this rifle but all it's really done is confuse the hell out of me. Has anyone else with an Rem 700 AAC-SD found it to lack a discern-able node?

Thanks for looking,
Sudboy

44 grns looks like it to me. 43.5, 44 & 44.5 are all grouped on the same spot on the target. Now load up 5 each at 43.7, 44 & 44.3 to verify it. They should all be grouped in the same area on the target. Shoot 5 foulers first.

Did I miss what bullet and brass you are using?

ETA...Did you shoot them in a round robin?

I decided it was a dumb question and deleted it.

Recipe is 168 gr noosler hpbt, M118 brass, federal match primer, varget, col 2.825 or so.

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With .308 and 165-168 grain match grade bullets, I have read many times that others found the same optimum with Varget as you. I am only now starting with precision rifle. I recently surprised myself at 300 yards with two groups of 1 1/8 and 7/8 with 43.8 grains of Varget and the Sierra Match King.

I shoot 175s, so I don't have a load worked up with Varget and a 168. But, you can go to the reloading section and look at the load database to get a good idea what others are finding for that bullet/powder combination. It's one of the tacked threads at the top. 2,650 fps seems to be the sweet spot on my rifle, but that really doesn't mean anything.

Either way, don't miss the forest for the trees. By that, I mean you have 3 decent looking groups that are all in the same part of the target and it looks like a decent sized node. I don't really know how much more accurate you need to be. If you can verify it, I'd run some seating depth tests and call that a load.

You could look for another node at a faster velocity, but work up slow and be very careful!!! It does look like you have some accuracy at 45.5, but the groups above it and below it fall apart which leads me to believe that it's a very shallow accuracy node. Not really what you are looking for in a OCW load.

43.5 looks good to me.

You want a charge weight that can vary upwards as well as downwards without falling too far from POA/POI.

Shoot it at longer ranges and see what happens.


Maybe do a few 10 round strings with the 43. 43.5 and 44 charge weights to see what you get?

45.5 grains looks like the tightest group in your photo. I'd take a long look at your cases for any issues loading that large a charge...just to be safe. It shouldn't be an issue, but I'm pretty cautious about that sort of thing.

Try your test again at 300 yds. It will become more obviously apparent which load is giving you the best results.

Then you might want to consider evaluating your load's 'jam/jump' or the seating depth as it relates to the projectile's distance from the L&Gs. This will also help tighten up the groups.

Load development is a pain in the ass....unless you just enjoy doing it....but once you arrive at the optimal load for a specific rifle....it's worth it.

I'm seeing two possibles there. One between 43.5 and 44 and the other around 45.5. Start .2-.3 below and above the first node and maybe a little more on the second. Now using the smaller increments in those areas, pick the group that resides between two other similar groups for your ocw. Then if not happy, adjust seating depth. At least, that's what I'd do.

My last Varget load was 43.5gr under the same bullet your using except my COL was 2.850"... shot amazing. Then again... everything shoots amazing out of my AI at 100 yards. I need to start shooting at 200 to see load potential

I got to brag though.. I came into 1k of those Nosler 168gr BTHP's for $200 and they seem to shoot really good.

I went through the same thing as you with the same rifle. I was shooting 168gr Berger VLD's with BL-C(2) though. I was confused too untill I shot at 300 yards and boy then you definatly tell which load is best. I have a load that shoots a 1" group at 100 yards but it will still shoot 1 1/4" at 300 while the other charges shot 2-3" groups at 300yds.
Shoot it a little further and you will see the difference.

Go back and retest at least 3 ten shot groups each from 43gr to 44.5 in .5 grain increments. 44.5gr target appears to be user error, so include that load.

When that is done, take your best 1 grain total spread and work up loads in .2 grain increments in the same manner as above.

When you are done, take your best TWO loads, from the previous test, and work with the seating depth and see if you can get improvements by loading closer to the lands if the magazine will allow. Those results will get you the most accurate load for that rifle.

Whenever I have done ladder testing, I always do it at 200 or 300 yards. You just can't see what you need to see when shooting at 100 yards. You don't get enough drop and the difference in drop from load-to-load just isn't there.

The other problem at 100 yards is aiming error. The tiny differences in point of impact could be due to aiming errors. What sights and reticle did you use? How big was your wobble zone? How accurately can you shoot or, put another way, how much of the variation we see is you and how much is the rifle/load? You need to come to grips with honest answers to questions like these when interpretting the results.

IMO, any load that requires you to go back and redo the testing at 0.2 gr increments is a total failure with respect to the general philosophy underlying OCW and ladder testing. Besides, 0.2 gr of powder is largely irrelevant in exterior ballistics.

An effective ladder test is one round of each load, all fired together. The goal is not to find which load works best, but to find which -range- of loads all behave the same. That way, when you load in the center of that range, you have consistency that is unaffected by small load errors and fluctuating environmental conditions.

Ex:
-load range is 42-46 grains.
-You load a 42, 42.5, 43, 43.5, 4, 44.5, 45, 45.5, and a 46.
-43, 43.5, 44, and 44.5 all noticeably group together. 42, 42.5, 45 and up do their own thing.
-load 10 rounds averaging your accuracy node at 43.7 grains and confirm.

-If weather and/or load errors cause your load to behave like loads anywhere from 43 to 44.5 grains, you're still shooting accurately.

I just did this today myself. I, like you, found that every load was in almost the exact same spot on the targets. I shot at 200 yds using 168 HPBT's. I started at 39.5 gr.'s of Varget and went to 42.5 gr.'s

39.5 was my best group, but I'm afraid it won't have the velocity to hold together at longer ranges. I loaded up several of the 42.5 gr.'s and am going to try them at 1, 2, 3, and 4 hundred yards tomorrow and see what I end up with.

I've got to get a chrono!

I think OP is using the OCW test not ladder.

The ladder test is probably more effective, but not everyone has access to 300 yards to test on. The OCW method is supposed to be effective at 100yards. The principal is the same for both methods though.

The ladder test would be fine if you never pull a shot and scatter nodes didn't exist. The point of the OCW is to minimize the effects of the shooter and randomness on the load development process. The guy who wrote up OCW suggests shooting it at 200yds as well.

I think both methods depend on an accurate shooter to be completely effective. Of course, if the shooter is 100%, then either method is effective. The human element is what makes precision shooting fun.

FOLLOWUP:

44.0 gr seems to do best with my rifle. Here's a pic of the results:


I am not this good a shot FYI. Pleased with how this turned out :-)


Sudboy

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