OCW - Rifle seems to always hit same spot regardless

[pmclaine]

Im doing a OCW of sorts for an Remington 700 24" heavy barrel. Did one target with small spreads between loadings and came away feeling my loads were light not really working good at distance. So I decided to load toward the heavier end of the .308 scale and see how things would go.

My first target




I made up some 41.9 and it did okay at 300 was good for five consistent hits on a torso at 500 plus.

41.9 at 300





Todays target using heavier charges





The rifle seems impervious to charge differences as far as my eye can tell. I think the only reason 44.6 fell apart is because some fellow shooters wanted to go down range and clear their targets causing about a ten minute delay in shooting.

Im really liking 43.0 of 4064 but that isnt the purpose of OCW. What do the real OCW dousers see for my fortune?

 

[RobertB]

I would play around to 44 Grn area with it and see how it does. If I had to just pick a load from what I see it would be 44gns. Fine tune on the load and then on the seating. And its the ladder test that looks for POI. OCW looks for groups. When I do an OCW test before I call something my load I go out to distance and check my vertical.

 

[RobertB]

OCW will get you load between sweet spots so that your load wont be picky if one case gets a bit more or less powder than another. It looks for a forgiving load. If you have a sweet group but the two on each side of it are bad then it ight not be right. But if you have one that has say 3 charges that look good you can pick the middle one and be safe. The ladder test you do the same thing but your looking for vertical differences to show a charge area that wont be picky on a charge and gives you roughly the same MV from shot to shot

 

[Jrb572]

I think your supposed to shoot one shot of each at the same aiming point and see which rounds group close and go from there.

 

[Dan Newberry]

looks like a scatter node at 42.4 grains, pointing backward toward an OCW at 41.8 grains, and forward toward the next node at 43.0 grains. It's pretty straight-forward.

44.2 would be the next node... it's going to be hotter of course, but the node should be there.

 

[pmclaine]

looks like a scatter node at 42.4 grains, pointing backward toward an OCW at 41.8 grains, and forward toward the next node at 43.0 grains. It's pretty straight-forward.

44.2 would be the next node... it's going to be hotter of course, but the node should be there.

41.8 was a good group. When I was shooting it my last shot I was thinking "Dont screw this up its a nice tight group" and of course I lost my sack and threw one outside the group.

43 and 44.2 were my best groups of the day today.

Now Ill go to your site Dan and see what step two is. Thank you for the feedback.

I really like reloading but truthfully development causes me a lot of consternation. The thought of wasting rounds and the wondering "Can this be better?" gives me agida. I just need a good consistent round and let the quality trigger time/practice on fundamentals make up for my insufficient loading practices.


EDIT - For instructional purposes only "GOOD GROUPS" means tight bullet pattern within a similar zone of impact to groups up or down the OCW load scale.

 

[Twoboxer]

Deleted: another reading comprehension error

 

[bruddah]

Do you know what your velocity was with those charges?

 

[pmclaine]

Do you know what your velocity was with those charges?

Sorry no. Theoretically 41.9 should be about 2600. No idea though.

 

[bruddah]

Sorry no. Theoretically 41.9 should be about 2600. No idea though.

Ok. Thanks!

 

[noylj]

If the shots were at 100 yards, I would just say that I thought the basis for the ladder/OCW test was to place the target 300 yards and fire one shot at each charge weight and note where each shot lands. The location where the rounds cluster over some range of charge weights was then investigated for accuracy. The original write-up was that the shooting had to be done at over 200 yards to mean anything.
From what I see, you simply did the traditional ?shoot groups with each charge weight and see what happens."
If I am wrong, sorry.

 

[pmclaine]

If the shots were at 100 yards, I would just say that I thought the basis for the ladder/OCW test was to place the target 300 yards and fire one shot at each charge weight and note where each shot lands. The location where the rounds cluster over some range of charge weights was then investigated for accuracy. The original write-up was that the shooting had to be done at over 200 yards to mean anything.
From what I see, you simply did the traditional ?shoot groups with each charge weight and see what happens."
If I am wrong, sorry.

Instructions here

OCW Overview - Dan Newberry's OCW Load Development System

The hope is that as you shoot your OCW you will be able to observe the effect of barrel harmonics on your POI and you will be able to identify the charge that shows wider tolerance or "bandwidth"where charges hit a common impact area. Dan explains it in a figure 8 pattern of two unequal ellipses we try to identify the major and minor nodes of accuracy while avoiding those areas where the rifle barrel is in an unstable period of movement results shown as a scatter node. In Dan's testing I understand that results follow a "constant" - if you identify the scatter node than accuracy nodes are a predictable percentage above/below the scatter node.

A ladder test is a different test.

OCW Overview - Dan Newberry's OCW Load Development System

Thats my understanding of what I am barely knowlegeable about.

 

[4Quangs]

If the shots were at 100 yards, I would just say that I thought the basis for the ladder/OCW test was to place the target 300 yards and fire one shot at each charge weight and note where each shot lands. The location where the rounds cluster over some range of charge weights was then investigated for accuracy. The original write-up was that the shooting had to be done at over 200 yards to mean anything.
From what I see, you simply did the traditional ?shoot groups with each charge weight and see what happens."
If I am wrong, sorry.

I'm new at this as well, so take my thoughts with a bit of skepticism.

The ladder test is looking for a sequence of single shots where the increase in the powder charge has minimal affect on the elevation of the point of impact. This is thought to indicate a range of powder charges to which your rifle is relatively insensitive and therefore, you're more likely to shoot better groups. At 300 yards, it is thought that the change in POI would be more obvious than at 100 yards.

The OCW test is looking for sequence of groups where the increase in the powder charge has a minimal affect on the POI of the center of the group. This method accounts for changes in both horizontal and vertical POI. Additionally, the OCW method recommends shooting the groups in a round robin fashion to eliminate the effects of shooter fatigue, barrel fouling, windage, etc.

 

[Pocoloco]

What weight bullet was this? If you posted it I didn't see it. Really nice groups.

 

[pmclaine]

What weight bullet was this? If you posted it I didn't see it. Really nice groups.

4064 powder

Nosler Custom Comps 168 grains

Win LRP

WCC 13 1X brass

2.8 COAL, No crimp, loaded on a Dillon S1050 with trickled charges after the powder drop.

Backpack used as front rest, rear of stock was on a bag. Sighters were fired consecutively. OCW test was fired Round Robin. Did not follow cleaning protocols but I did give +/- 2 minutes cooling between all shots unless noted otherwise.

Distance was 100 yards.

 

[Pocoloco]

Thanks, Dan Newberry had found that Federal's load for the 168 was 42.8 of 4064. Your gun seems to like them all.

Good shooting

4064 powder

Nosler Custom Comps 168 grains

Win LRP

WCC 13 1X brass

2.8 COAL, No crimp, loaded on a Dillon S1050 with trickled charges after the powder drop.

Backpack used as front rest, rear of stock was on a bag. Sighters were fired consecutively. OCW test was fired Round Robin. Did not follow cleaning protocols but I did give +/- 2 minutes cooling between all shots unless noted otherwise.

Distance was 100 yards.

 

[pmclaine]

Thanks, Dan Newberry had found that Federal's load for the 168 was 42.8 of 4064. Your gun seems to like them all.

Good shooting

My initial loading was 42.8. I hoped it would prove magic in my rifle as in so many others but my 168 remanufactured was outshooting it so I went the OCW route.

Im going to load some 43 and 41.8 and 44.2, to try at 300. Ill update with results.

Weird thing about the 42.4 scatter node - Fired round robin I see the group fell apart but in the sighter target on tht OCW I fired 5 consecutive 2.4 and they fell right in with the 5 factory reman bullets I used for fouling/warm up. Ill give the round robin factor extra weight in showing the "scatter effect" of the loading.

 

[pmclaine]

Fired my the three loads that looked most promising at 100 yards on the 300 yard range today. Didnt get the results I expected. Seems like the rounds I intended to use only for sight in and bore warm up outshot the OCW loads.....



41.8



43



44.2

 

[pmclaine]

My 42.6 sighters



The sighters I shot one after the other from the magazine. The different work ups I shot round robin. I screwed up a windage correction after sight in stupidly putting in right when I want impact to go left. The 41.8 would have been pretty tight through 6 shots had I not made that mistake. 42.6 was only to get inside the 6 inch circle and the group looked pretty good. 42.6 is a load that seems to want to work with my LMT MWS. Im thinking to confirm its suitability in the MWS and the M40A1 and hope that I can get one load for two guns.