Good OCW....opinions...

[KOPFJÄGER13]

Hey guys, shot this OCW today, shot it round robin.... I wrote the average velocity & extreme spread for ya to consider also..... let me know what you guys think, thanks in advance & all feedback is welcome! Btw, it was shot from the prone out of the bed of my truck @100y off a bipod....

 

[lash]

No matter how many times I look at it, I like the range from 44.9-45.3

 

[KOPFJÄGER13]

No matter how many times I look at it, I like the range from 44.9-45.3

For what reason? I'm not saying I agree or disagree.... just curious why that range stands out?

 

[SFeldt]

I would try 45.0 gr and maybe mess with seating depth.

 

[SFeldt]

What are you running? Cartridge brass bullet primer powder?

 

[KOPFJÄGER13]

What are you running? Cartridge brass bullet primer powder?

308 155gr scenar
Lapua brass (was full sized for test)
Cci 200
Varget
Coal was 2.855" (mag length)
.040" jump (if I remember right)

 

[KOPFJÄGER13]

46.1 seemed to be the spot in my opinion I had a weird trigger pull on the 3rd loose shot but the velocity was literally the same all three shots which seems to me to be bout perfect considering it was shot round robin.... if I'm wrong please correct me and face me in the correct direction

 

[SFeldt]

Yeah I would load up 20 with 45.0gr to shoot at distance and check ES. I dont think the scenars are that sensitive to seating depth.

 

[KOPFJÄGER13]

Yeah I would load up 20 with 45.0gr to shoot at distance and check ES. I dont think the scenars are that sensitive to seating depth.

That's interesting to me that you chose that and suggested checking the extreme spread but 46.1 literally had 0 fps ES...... ?

 

[SFeldt]

Look at the ES of 19 above and below. That's why I say that.

 

[lash]

For what reason? I'm not saying I agree or disagree.... just curious why that range stands out?

My opinion of what you’re trying to accomplish with OCW testing is to determine the most forgiving load range, or node. The way you do this is to watch for changes in the triangulated center of the POI with respect to the POA. If you review the three loads at 44.9, 45.1, and 45.3, the triangulated centers of each “group” are exactly the same.

What that means to me, is that you have found a node where variations in loading and environment have little impact. For my purposes, that meets my needs. Not everyone is looking for the most forgiving load, though, so if you are looking for the most accurate (read as tightest group) without regard to potential variations in the load or environment, you might choose something different.

 

[Deleted member 113831]

POI is virtually flat from 44.9-45.5.
These forgiving loads very often show up between 1.5%-2% off of max.
You hit book max velocity at 46.3
Max minus 1.5%-2% equates to 45.3-45.6 grains.
45.7 is exactly where you POI dropped and started to move up and down more drastically

I would choose 45.3, and seat your bullets a bit deeper to better contact the powder column and I bet your SD decreases. These 155's don't have much bearing surface to begin with, seating them out doesn't do them any favors.

Just my opinion

 

[KOPFJÄGER13]

Look at the ES of 19 above and below. That's why I say that.

"ES of 19 above & below"....??... isnt the lowest possible ES optimal, doesnt that make the biggest difference at extended long range?.... now I'm confused, lol

 

[KOPFJÄGER13]

Shookum.... I see what your saying, I'll look at that....

 

[lash]

"ES of 19 above & below"....??... isnt the lowest possible ES optimal, doesnt that make the biggest difference at extended long range?.... now I'm confused, lol

Yes, but...

You have to have a load that will withstand variations in your environmental and loading conditions. Will that 0 ES stand up when it’s 30 degrees F hotter or colder? Or if your load prep and process isn’t exactly the same each time? What about different lots of powder, primers, aging brass, neck tension?

Oh, and that is an ES based on three shots. Try loading up 30 rounds of that load and see if the ES stands up to that over the whole batch. If it does, you may have beaten the odds.

 

[KOPFJÄGER13]

Yes, but...

You have to have a load that will withstand variations in your environmental and loading conditions. Will that 0 ES stand up when it’s 30 degrees F hotter or colder? Or if your load prep and process isn’t exactly the same each time? What about different lots of powder, primers, aging brass, neck tension?

Oh, and that is an ES based on three shots. Try loading up 30 rounds of that load and see if the ES stands up to that over the whole batch. If it does, you may have beaten the odds.

Oh , I apologize, I misunderstood.... I see exactly what your saying, I totally agree..... thanks for clarifying

 

[KOPFJÄGER13]

Now based on poa/poi it seems any would work....relatively, right?

 

[SFeldt]

"ES of 19 above & below"....??... isnt the lowest possible ES optimal, doesnt that make the biggest difference at extended long range?.... now I'm confused, lol

Sorry I should of been more clear above and below 46.1. Seem unstable for changing environmental conditions. +skookum makes a fantastic point about poi.

 

[lash]

Now based on poa/poi it seems any would work....relatively, right?View attachment 7328095

As already noted by Skookum, at 45.5 your ES and speed jump up as it approaches a poi shift. Note the shift between 45.5 and 45.7. 45.7 is your scatter node with a speed that is much higher than anything on either side of it. And your favorite 46.1 is right before another poi shift at 46.3.

I don't claim to be an OCW expert, but you asked what we think, so I answered.

 

[KOPFJÄGER13]

That all makes good sense guys, thanks!

 

[Doom]

I hate to say this but I don't see enough consistency to make aan OCW call here. I will make a guess that 45.7 is a scatter node. That would suggest that the nodes are somewhere around 45.1 and 46.3. You might try this loads again.

 

[MarkTheNewf]

.

 

[KOPFJÄGER13]

Please correct me if I'm off with any of this as I'm kinda an OCW noob, but what I've seen/read, shouldn't you be:
a) Shooting 5 rounds/load for a better representation
b) looking at SD not ES?
c) looking at vertical spread moreso than horizontal?

I've always looked at SD and always tried to keep them at 12 or less, preferably in the single digits.

A) 5 round groups can help ya read more accurately if there's a predisposition to flyers but not necessary in an ocw...
B)ES gives you a "bigger window" to look through, though both ES & SD work
C) Yes, vertical dispersion is what your looking for due to it being an indicator of velocity fluctuations

....... of course that's my opinion and I'm sure there's alot of keyboard snipers that will want to argue this, lol

 

[KOPFJÄGER13]

I hate to say this but I don't see enough consistency to make aan OCW call here. I will make a guess that 45.7 is a scatter node. That would suggest that the nodes are somewhere around 45.1 and 46.3. You might try this loads again.

Heres my personal read of this test....
45.7-46.1 is where I should be looking, why some will ask.....well the velocity is very close with 45.7 & 45.9, and the ES is less between 45.7 & 46.1 than any other 3 consecutive charges which implies a very stable load...... and the center of the groups are very very close as far as POI, showing stability in barrel harmonics..... group size & shape is irrelevant, it can be improved alot with seating depth & neck sizing only and the POI can be cured simply zeroing the scope

 

[lash]

Please correct me if I'm off with any of this as I'm kinda an OCW noob, but what I've seen/read, shouldn't you be:
a) Shooting 5 rounds/load for a better representation
b) looking at SD not ES?
c) looking at vertical spread moreso than horizontal?

I've always looked at SD and always tried to keep them at 12 or less, preferably in the single digits.

SD over 3-5 rounds has almost no statistical meaning.

Not at shot at you, but have you actually read the full text of how to do an OCW workup by Dan Newberry? Your suggestions would indicate that you haven’t.

link to OCW website:

Home

 

[supercorndogs]

Please correct me if I'm off with any of this as I'm kinda an OCW noob, but what I've seen/read, shouldn't you be:
a) Shooting 5 rounds/load for a better representation
b) looking at SD not ES?
c) looking at vertical spread moreso than horizontal?

I've always looked at SD and always tried to keep them at 12 or less, preferably in the single digits.

Not OCW.

 

[Dthomas3523]

Common mistake at seeing a zero SD or ES and wanting to run with it.

The reason you need to look at the chrono numbers above and below is you’re looking for a powder node that is stable. When something in the environment changes, it pushes you up or down. If you’re not in a stable node, then you are pushed up or down into instability.

This is why you hear guys say “my rifle shot awesome yesterday at home, but when I got to (wherever) it shot like shit.” They weren’t in an actual node.

This is also why it’s becoming more common to find powder node with chrono only and no groups. Then adjust seating depth to find a seating node that works with your powder node.

There is also the question of how reliable your chrono numbers are in the long run.

Based on the info provided, if you’re pretty meticulous with things like neck tension and charge weight, load 5rnds from 44.7-45.3 (45.0 seems to be where you want to be) and see if the node holds up. If you’re not meticulous, you may need 10rnds each time get reliable data.

Or, just run with 45.0 and do seating depth tests.

 

[Dthomas3523]

Also, what chrono was used? If magneto.....groups ain’t gonna mean much of anything.

 

[KOPFJÄGER13]

Also, what chrono was used? If magneto.....groups ain’t gonna mean much of anything.

It's a competition electronics prochrono-pal

 

[Dthomas3523]

It's a competition electronics prochrono-pal

Ah. Personally, if it’s not magneto, Labradar, or oehlar, I don’t trust it.

 

[KOPFJÄGER13]

Hey guys, I reshot these 3 loads with 5 shots each, heres the groups with individual velocities.... disclaimer - shot these off a shitty bench lol

 

[KOPFJÄGER13]

Ah. Personally, if it’s not magneto, Labradar, or oehlar, I don’t trust it.

Yea not the best , usually I can get close by throwing the high & low out..... it's what I got so I make due

 

[Doom]

What make and type is the rifle? Barrel length? What kind of groups do you get with factory ammunition?

 

[KOPFJÄGER13]

What make and type is the rifle? Barrel length? What kind of groups do you get with factory ammunition?

Factory remington 700 5rmilspec.... 24" barrel, 1-11.25 twist.... I've never shot factory ammo through it I dont think.... however itll shoot under 1 inch regularly with my 168 smk load

 

[Doom]

What load are you running with the 168?

 

[Kadams1563]

I can look at OCW test all day and I cant seem to decipher any of them. Just something my brain cannot get I guess.

All of the groups look like shit when I do them.

 

[supercorndogs]

Its a lot easier to see the POI shift on a grid with an accurate rifle. When bullets are splattered all over, its hard to tell. I would not mess with a bullet that printed 2 moa in an OCW test. I would be straight on to the next bullet. I didn't have a guess from looking at the test. Most of my loads hold true to what Skookum said.

 

[KOPFJÄGER13]

What load are you running with the 168?

43.1 sir...... and it's a solid 3/4 moa load

 

[KOPFJÄGER13]

Its a lot easier to see the POI shift on a grid with an accurate rifle. When bullets are splattered all over, its hard to tell. I would not mess with a bullet that printed 2 moa in an OCW test. I would be straight on to the next bullet. I didn't have a guess from looking at the test. Most of my loads hold true to what Skookum said.

I wouldnt use one that printed 2moa myself.... but OCW isnt really about group size

 

[supercorndogs]

You set up a test that vaguely resembles OCW, and now you're the expert. Par for the course online. I am sure that bullet will shoot great, when you do your part.

 

[KOPFJÄGER13]

You set up a test that vaguely resembles OCW, and now you're the expert. Par for the course online. I am sure that bullet will shoot great, when you do your part.

If it's not an OCW then what is it..... and am I wrong about it not really being about group size? "I'm the expert" ... no not really but I'm no spring chicken..... but thankfully I have access to know it all asshole keyboard snipers on here

 

[Dthomas3523]

If it's not an OCW then what is it..... and am I wrong about it not really being about group size? "I'm the expert" ... no not really but I'm no spring chicken..... but thankfully I have access to know it all asshole keyboard snipers on here

Most everyone has pointed you more towards 45.0 ish where your ES was low and stable.

You went with something else because you saw a zero and now you’re messing with unstable and the zero went to a 44.

 

[KOPFJÄGER13]

I haven't settled yet, ive got the same thing coming with 44.9, 45.1 & 45.3....we will see!

 

[supercorndogs]

If it's not an OCW then what is it..... and am I wrong about it not really being about group size? "I'm the expert" ... no not really but I'm no spring chicken..... but thankfully I have access to know it all asshole keyboard snipers on here

Maybe go read the material on OCW, rather than basing your test on a notion. Your development has led you to three near 2 moa 5 shot groups with a different POI, across .4g of powder. If you are in a node, there is something wrong with your gun, or your shooting. If you and your gun shoot 3/4 MOA with something else. Your gun may not like that bullet. Below its what you read to learn how to do an OCW. Below that is an explanation from that material of what I said.

OCW instructions - Dan Newberry's OCW Load Development System

Dan Newberry OCW or Optimal Charge Weight Load Development method or system for handloading, reloading, bullets, brass, powder, primers, accurate handloads.

optimalchargeweight.embarqspace.com

19. The OCW load development plan works best with rifles and shooters that are actually capable of MOA accuracy. If your rifle has not shown a propensity for reasonable accuracy, you may want to have it corrected before wasting time and material with additional load developement. If you are not confident that you are at a level where you can shoot consistent MOA groups, you may want to hold off on intricate load development until your skills are better honed. Lots of practice with a scoped .22 LR is invaluable...

 

[Doom]

43.1 sir...... and it's a solid 3/4 moa load

That’s a good load. I’m not sure your rifle is going to like the Scenar. Looking at your groups there is definately a lack of repeatability. The Remingtons are noted for having long throats. Trying to seat the Scenar to .040” off the lands may not be leaving you with enough bullet in the neck to get consistent neck tension.

I would at least try seating to 2.800” and try these loads again. You can leave the Chrony at home. I also recommend you check Dan Newberry’s site.

You may also find this of interest

Practical Riflery and OCW Forums-308 155 Scenar/Varget

I was hoping someone could lend some insight as to what is happening as far as my OCW results go. Some background, I had a reliable load shooting in t

www.tapatalk.com

 

[KOPFJÄGER13]

That’s a good load. I’m not sure your rifle is going to like the Scenar. Looking at your groups there is definately a lack of repeatability. The Remingtons are noted for having long throats. Trying to seat the Scenar to .040” off the lands may not be leaving you with enough bullet in the neck to get consistent neck tension.

I would at least try seating to 2.800” and try these loads again. You can leave the Chrony at home. I also recommend you check Dan Newberry’s site.

You may also find this of interest

Practical Riflery and OCW Forums-308 155 Scenar/Varget

I was hoping someone could lend some insight as to what is happening as far as my OCW results go. Some background, I had a reliable load shooting in t

www.tapatalk.com

Thanks doom! That was an interesting read for sure......

 

[KOPFJÄGER13]

So I went out with 10 rounds of the 45.9g loads and shot (2) 5 round groups at 300y.... 1 I didnt pay much attention to wind & the other I waited for what wind I had to die down and this is how it shot....

 

[KOPFJÄGER13]

Sure glad it's not a 2moa shooter...

 

[Dthomas3523]

Sure glad it's not a 2moa shooter...

Were those two targets oriented the way the pictures show them? If so and you didn’t mess with elevation turret you have either shooter or load problems.

Vertical POI is pretty far from one another.

 

[KOPFJÄGER13]

Were those two targets oriented the way the pictures show them? If so and you didn’t mess with elevation turret you have either shooter or load problems.

Vertical POI is pretty far from one another.

Yes they were oriented as shown, and yes I messed with turrets..... the scope isnt zeroed for this round and all I was going for was group size, the poi had no bearing, it was just to see if it grouped well......