223 OCW analyzing

[timelinex]

So I finally put a scope on the 223 Daniel Defense and tested some loads. My components are as follows:

1x fired LC brass
#41 primers
8028XBR powder 22.2gr --> 23.8gr
77gr Sierras seated to just about mag length

The day was hot with alot of mirage and had wind that was going back and forth between 0 and 5 mph. I did not correct for the wind, which explains some of the lateral spread.

Here is the target:

22.2 gr actually starts at the bottom left and then it goes backwards. In case you can't see it too well, my vertical distance from POA, starting from 22.2gr and going to 23.8 gr are:
.75”
.46”
.91”
.79”
1.1”
.95”
1.3”
1.1”
1.2”


This is what I think... I think that 22.6-23.0 gr is a scatter node and then 23.2 is the beginning of a node that goes farther than the 23.8 I tested to. I believe my next step is to do .1gr increments from 23.6 to 24.3. If I confirm its a node, what do I do next? Usually I would play with seating, with a middle of the node charge, and that would tighten the groups. Since I am constrained to mag length, is this as good as it gets?

What do you guys think??

 

[oldfatguy]

Re: 223 OCW analyzing

If I were shooting that OCW workup I'd concentrate on group 4 and explore seating depth with 5 rnd round robin groups. Good for the short line but if you are going to 600+ yds then looking at more velocity might be where to go.

OFG

 

[timelinex]

Re: 223 OCW analyzing

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: oldfatguy</div><div class="ubbcode-body">If I were shooting that OCW workup I'd concentrate on group 4 and explore seating depth with 5 rnd round robin groups. Good for the short line but if you are going to 600+ yds then looking at more velocity might be where to go.

OFG </div></div>

I'm assuming that by group #4 you mean the upper right group?

Isn't it pretty close to the scatter node right before it?

Also, how can I play with seating depth if I'm already seated into as far as the mag will let me. Usually, I find groups tighten up when you seat them closer and closer to the lands. Do you suggest I try to seat them even shorter?

 

[Gene Poole]

Re: 223 OCW analyzing

Kinda hard to read. As far as wind, at 100yd, you'r not gonna see much horizontal dispersion with a .223. I'd tend to want to discount the upper left shot on group 3, but then looking at group 5, you have about the same average dispersion but no obvious outlier, but group 6 is way too tight to think that the dispersion in 5 is normal for a 0.2 gn change.

I alway load 5 each for my OCWs and if I see something like this, a shoot two more each on groups 3 and 5 to see for sure.

My gut says that the upper left shot in group 3 is a fluke and should be closer to the others in which case, you've got a node center at about 22.6, but overall, the signal to noise ratio seems too high make a judgment on these data alone.

I'd recommend another try, maybe at 200 yd or so if you can since .223 is so flat at 100. Load 5 each and if you get a seemingly odd shot, reshoot two more after your overall test with three each.

 

[oldfatguy]

Re: 223 OCW analyzing

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: timelinex</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: oldfatguy</div><div class="ubbcode-body">If I were shooting that OCW workup I'd concentrate on group 4 and explore seating depth with 5 rnd round robin groups. Good for the short line but if you are going to 600+ yds then looking at more velocity might be where to go.

OFG </div></div>

I'm assuming that by group #4 you mean the upper right group?

Isn't it pretty close to the scatter node right before it?

Also, how can I play with seating depth if I'm already seated into as far as the mag will let me. Usually, I find groups tighten up when you seat them closer and closer to the lands. Do you suggest I try to seat them even shorter? </div></div>

<span style="color: #CC0000"><span style="font-weight: bold">group 4</span></span> ________ No, I was looking at the second row, second group from the left as being labeled "group 4". The center of that group is close, but not exactly, to the ones before and after. As I understand OCW similar POIs are what you are supposed to go by, not the size of the groups.

On a 260 Rem the rifle liked to jump 107 SMKs 0.020". Loaded from 0.010" jammed to 0.090" jump in 0.010" steps. If your rifle likes them loaded longer then will fit into your mag you may have to single load.


OFG

 

[sinister]

Re: 223 OCW analyzing

Try 10-shot groups at 300.

At 100, as noted, you're not going to see much vertical dispersion so what's the point (especially with 3-shot groups)? Your sample lot sizes are awfully small -- I wouldn't want to base a lot of say 500 rounds on single three-shot groups I didn't correct for wind and mirage.

If you're not correcting for wind and mirage then your horizontal dispersion isn't going to matter either and your group sizes will be random as well (especially if the gun isn't mechanically rested).

If you're just planning on shooting at 100 then I'd pick one of the combos you've already fired and just start blasting. It's a self-loading assault rifle, not a single-shot benchrest rifle. How do you intend to use the rifle, and what scope are you using (i.e., what is the optimum you're seeking, and is this ammo going to be used with other rifles as well)? Paper-punching, coyotes, prairie dogs? What are the specifics on the weapon? Is this a short-barreled rifle, a standard 16-inch carbine, or a heavy-barreled/free-floated precision gun?

What specifically are you asking us to help you with?

 

[oldfatguy]

Re: 223 OCW analyzing

Dan Newberry's OCW method uses 3 shot "groups" at 100 yds. What is important is the relative locations of the group centers, ie: POIs. The POIs that are close to being in the same location relative to the POAs define the accuracy node(s).

Ten round groups at 300 with wind and mirage corrections shot from a mechanical rest are an entirely different animal.

OFG

 

[timelinex]

Re: 223 OCW analyzing

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Gene Poole</div><div class="ubbcode-body">Kinda hard to read. As far as wind, at 100yd, you'r not gonna see much horizontal dispersion with a .223. I'd tend to want to discount the upper left shot on group 3, but then looking at group 5, you have about the same average dispersion but no obvious outlier, but group 6 is way too tight to think that the dispersion in 5 is normal for a 0.2 gn change.

I alway load 5 each for my OCWs and if I see something like this, a shoot two more each on groups 3 and 5 to see for sure.

My gut says that the upper left shot in group 3 is a fluke and should be closer to the others in which case, you've got a node center at about 22.6, but overall, the signal to noise ratio seems too high make a judgment on these data alone.

I'd recommend another try, maybe at 200 yd or so if you can since .223 is so flat at 100. Load 5 each and if you get a seemingly odd shot, reshoot two more after your overall test with three each. </div></div>

I didn't call any fliers, of coarse its possible I pulled one anyways. BUT on the other hand, I am using pre-procesed 1x fired Military brass, so I would expect more fliers compared to my other calibers that I use fire formd and self fully processed brass.

So what do you guys see in the 22.6 gr range rather than the 23.6 gr range.

The rifle will be used with either irons or eotech 95% of the time, so it's not exactly going to be a long range precision rifle. I was just hoping to find a nice wide node that would absorb most the variations in military brass with lack of prep and still print a solid <1moa.

The 22.6 node seems to be doing a bad job at this, however 3 shot groups aren't the best tell's. I thought the 23.6 range seemed to be doing a good job.

What do you guys think?

I think that I will probably just load 10 rds of both 22.6 and and 23.6 and see which does better at 100 and 200 yards. And maybe load 5 round of each, measuring the powder less accurately, to see how well the node absorbs the differences.

 

[Gene Poole]

Re: 223 OCW analyzing

The point of OCW is to find a node that is relatively flexible with respect to powder weight, so that you could, say, use a thrower that may vary by 0.2 gn either way. I don't know that it would absorb other deficiencies in the reloading process as you stated.

One of the hardest things to get over with OCW is looking for tight groups. You'll want to fixate on those, but they aren't necessarily going to be as tight if you vary your charge by 0.1 or 0.2 gns, or if the outside temp changes 20 degrees, etc. You can tighten up the group with seating depth changes once you find a reliable node.

 

[timelinex]

Re: 223 OCW analyzing

Gene,
I hear you on what your saying. I have just never had or seen anyone else's OCW as defined and clear as the ones that Dan posts as examples. For example, the entire upper half of what i tested is all within .2" of each other. My mark 4 FFP reticle covers up the entire half inch dot , so while I'm confident in my hold, I can easily be off by .1" and not even know it. Then the fact that its only a 3 shot group and all three can easily be on the upper or lower half of the random dispersion circle. All this seems to muddy the waters so much that I would be hard pressed to believe .2" makes any significance.

On the other hand, I can see that the upper half and the lower half have pretty distinct different poi's and that between them I'm seeing a scatter pattern in my groups, which follows the theory that there's a scatter node between nodes. So this is how
I Came up with 23.6 as being my node. Do I have flawed logic here?


Also, since this is a semi that I will not be single loading. Is there a point in trying to change seating depths to shorter than mag length? I've usually found that seating closer to the lands, or into them, tightens up the groups and not seating farther.

 

[Gene Poole]

Re: 223 OCW analyzing

Well, as I mentioned, I think there's too much noise here to make any definitive call. That's why I said my "gut" feel was what it was. I think you need to try again or a few more times to confirm or even try to do a ladder test to help augment your data.

I had no idea what a Daniel Defense was after my first post, but now that I know it is a gas gun, I don't know what to tell you. I've tried a half-dozen times to get some OCW data for my M1A and it all looks like buck shot. I ended up just using a known good load from my bolt gun in the gas gun and it seems to do OK.

 

[timelinex]

Re: 223 OCW analyzing

Gotchya, maybe I should have made it more clear that it's an ar15.

I think I may be over thinking his on my end, since it's a gas gun and not my 338 or 308 bolt rifles that I'm used to loading for.