OCW .....opinions?

[FN in MT]

Ran the OCW test @ 100 yards this morning before the wind came up.

Rem 700, .308 win, 26.5" barrel
Varget, new Lapua brass, Fed 210M, 175 gr Berger VLD's
56 degrees 0-3 mph wind



I only had 3 sighters...... I ended up "sighted in" at basically 9:00 or 10:00 on the triangle. I probably should have cranked in some down and over.

FN in MT

 

[GSRswapandslow]

try shooting farther out....200-300 yards

but it's aparent there's a node at 43.3 and 44.5, what were the chrono readings for your es and sd at those loads?

also...were these all at the same seating depth?

 

[dustinoif3]

Any pressure signs at 44.5? I would run another test with 44.1, 44.3, 44.5 and 44.7. 44.5 is money this test will tell you the middle charge in that node

 

[FN in MT]

NO chrono readings. I was trying to beat the wind this morning didn't want to set up the Oehler. Too time consuming, uneven ground, etc.

OCL all the same @ 2.880".

Few weeks back 44.3 of Varget 175 gr Berger LR not the VLD's gave me 2677 fps, ES of 7 FPS.
175 gr GMM gave me an average of 2640 fps.


NO pressure signs at 44.5 grs. I did start to see FAR flatter primers, no more rounded edge, more of a FLAT edge, at 45.3 grains.


I ran some loads a week or so back with the last of the Berger 175's the LR #34020 that I had. I shot the VLD's today as I just got in two boxes of them.

Yes I agree I need to get out at 200 or 300 yds. Probably not until the weekend or early next week. We have a weather system moving in the next few days, going to be too windy. wind is at 11 mph right now.

Appreciate the learned input. I'm not new to reloading or shooting, but new to the LR/Precision end of it.

 

[Dan Newberry]

I would work with 43.1 grains. When you get to 43.7 you can see that one shot of the three "reaches" toward the new POI which is farther right, evident in the 44.1 grain group. By the way, had you shot two ladder tests, you might have been fooled into thinking that the node was centered closer to 43.7 grains, but the third shot at that charge level revealed the instability of 43.7 grains.

If you stick with 43.1 grains and work with the seating depth just a bit (or not, accuracy is probably going to be good there without any further tweaking)... you'll have a good, repeatable load.

The next node is going to be around 44.5 grains, but that area does not look near as stable or forgiving as the 43.1 grain charge should have you.

Dan

 

[FN in MT]

I would work with 43.1 grains. When you get to 43.7 you can see that one shot of the three "reaches" toward the new POI which is farther right, evident in the 44.1 grain group. By the way, had you shot two ladder tests, you might have been fooled into thinking that the node was centered closer to 43.7 grains, but the third shot at that charge level revealed the instability of 43.7 grains.

If you stick with 43.1 grains and work with the seating depth just a bit (or not, accuracy is probably going to be good there without any further tweaking)... you'll have a good, repeatable load.

The next node is going to be around 44.5 grains, but that area does not look near as stable or forgiving as the 43.1 grain charge should have you.

Dan

Appreciate the comments. What do You suggest I do from here? Go up and down .1 or .2 grs from the 43.1 gr load? I could also try different primers.

I may investigate the next node up 44.5 grs simply for the experience.

Would you suggest foing to 4 or 5 shot groups for the final tests/

FN in MT

 

[Dan Newberry]

I'd stay at 43.1 for that particular node, and if anything try a few different seating depths. Adjust the seating depth in .005" increments from where it was for the OCW test--and test the original depth one more time as well.

If your velocity is above 2600 fps at 43.1 grains (which I would think it would be) I'd probably work in that area, as you don't want to over exert your brass...

Dan

 

[FN in MT]

Thank You Dan. Nothing like information direct from THE MAN.

Hopefully I can get another target posted this weekend. Also hoping to get paper out to 300 yds.

FN in MT

 

[Pinecone]

I see many people looking at the smallest groups, not the series of groups with similar POIs.

 

[simplerider]

Dont get hung up on the tiny groups. Remember, you did an OCW test, not best group test. The purpose of an OCW is to find the charge range your rifle prefers. The 44.5 gr 1/2 inch group is nice but if you throw a charge 0.4 gr high or low, it becomes a 1 1/2 inch group and its ruined. Looking at the 43.3 gr 1/2 inch load, if you throw a charge up or down .4 gr your still in the same point of aim and still within 1 MOA (or smaller). The 43.7 gr load starts to open up a bit, so I'm guessing you will find the best results between your 42.9 and 43.3 loads.