Help with OCW test

[TaperPin]

I think you’re doing just fine with 3 shot groups as long as you shoot additional groups and overlap them with the original group.

Shooting more rounds will never reduce the size of a group. Shooting more rounds with the groups with worst accuracy is a complete waste of time. That makes no sense.

Had you shot 10 round groups, that’s 70 rounds. 3 shot groups were only 21 rounds and I’d only reshoot the three at the top - 6 more shots at each of those is only 18, for a total of 39 rounds - giving the same information as 70 rounds.

Blindly shooting 10 round groups for everything is one of those misuses of statistics that is perpetuated by well meaning guys trying to do the right thing. It’s an attempt to fire a large enough group to ACCEPT groups as good, where as small shot numbers are much quicker to REJECT a group as bad.

I’ll go so far as to say if two rounds gives a big group, don’t fire the third shot. Same for shots 4 through 9 or 10 - stop as soon as it’s too large to be seriously considered. Don’t ever fire that combination again - there’s no reason to ever retest a rejected group because no additional shots will ever reduce the group size.

As others have suggested, what happens now with the barrel will be different after 100 rounds have been fired.

 

[Highvoltage1]

Ryan Furman from Long Range Only has 2 videos on load development on YouTube, 1 with ocw and the other shooting a ladder at distance. They have helped me tremendously. Consider giving the ocw video a view, I think you will it pretty valuable. Best wishes.

 

[Packmansion]

I think you’re doing just fine with 3 shot groups as long as you shoot additional groups and overlap them with the original group.

Shooting more rounds will never reduce the size of a group. Shooting more rounds with the groups with worst accuracy is a complete waste of time. That makes no sense.

Had you shot 10 round groups, that’s 70 rounds. 3 shot groups were only 21 rounds and I’d only reshoot the three at the top - 6 more shots at each of those is only 18, for a total of 39 rounds - giving the same information as 70 rounds.

Blindly shooting 10 round groups for everything is one of those misuses of statistics that is perpetuated by well meaning guys trying to do the right thing. It’s an attempt to fire a large enough group to ACCEPT groups as good, where as small shot numbers are much quicker to REJECT a group as bad.

I’ll go so far as to say if two rounds gives a big group, don’t fire the third shot. Same for shots 4 through 9 or 10 - stop as soon as it’s too large to be seriously considered. Don’t ever fire that combination again - there’s no reason to ever retest a rejected group because no additional shots will ever reduce the group size.

As others have suggested, what happens now with the barrel will be different after 100 rounds have been fired.

No one said to blindly shoot 10 shot groups. Work up to max one round at a time no groups, so 7 loads in this case. Then load 10 at your desired velocity. If it's not accurate change a major component. This means you only shoot 17 rounds total to develop your load and if your 10 shot group is satisfactory then you're good. It's quite easy to shoot a 3 shot sub moa group because imagine your gun is a true 1.5 moa gun. Well draw 1.5 moa circle, if you randomly place 3 rounds in the circle and they happed to be average of 0.5 that doesn't mean your gun is 0.5 moa and this is totally possible. I bet if you load up 10 of #7 you will print a larger group. I'd bet if you took two separate loads and did 10 shots each they would have very similar accuracy. Cherry picking incomplete data is the equivalent of blidnly shooting groups. When shooting a 10 shot group it is best to adjust your scope 2 moa up or down so that you do not obscure your target with holes as this will inadvertently increase your group size as your point of aim will be harder to judge. This approach is better by Hornady. Hornady did a bunch of testing they immediately realized the following, nodes don't exist . 3 shot groups are a waste of time and tell you nothing. 10 shot groups are about the minimum you need to determine rifle/load accuracy. OAL and charge weight have little impact on accuracy. Changing major components makes the biggest difference. If you really want to know the true accuracy of your rifle/load then you need to shoot out the barrel with that load and do a 2000+ round group. It's like polling, they ask 5000 people who they will vote for and they extrapolate, you don't know until everyone votes. The smaller the sample the greater the margin of error. Decide how much margin of error you want.
It's a long video:

 

[TaperPin]

No one said to blindly shoot 10 shot groups. Work up to max one round at a time no groups, so 7 loads in this case. Then load 10 at your desired velocity. If it's not accurate change a major component. This means you only shoot 17 rounds total to develop your load and if your 10 shot group is satisfactory then you're good. It's quite easy to shoot a 3 shot sub moa group because imagine your gun is a true 1.5 moa gun. Well draw 1.5 moa circle, if you randomly place 3 rounds in the circle and they happed to be average of 0.5 that doesn't mean your gun is 0.5 moa and this is totally possible. I bet if you load up 10 of #7 you will print a larger group. I'd bet if you took two separate loads and did 10 shots each they would have very similar accuracy. Cherry picking incomplete data is the equivalent of blidnly shooting groups. When shooting a 10 shot group it is best to adjust your scope 2 moa up or down so that you do not obscure your target with holes as this will inadvertently increase your group size as your point of aim will be harder to judge. This approach is better by Hornady. Hornady did a bunch of testing they immediately realized the following, nodes don't exist . 3 shot groups are a waste of time and tell you nothing. 10 shot groups are about the minimum you need to determine rifle/load accuracy. OAL and charge weight have little impact on accuracy. Changing major components makes the biggest difference. If you really want to know the true accuracy of your rifle/load then you need to shoot out the barrel with that load and do a 2000+ round group. It's like polling, they ask 5000 people who they will vote for and they extrapolate, you don't know until everyone votes. The smaller the sample the greater the margin of error. Decide how much margin of error you want.
It's a long video:

Even the Hornady guys have said that their stance on nodes is for the average reloader and is not applicable to all forms of shooting. The entire industry built around accuracy raked them over the coals for it. Nodes win matches.

The idea that powder charge has no influence on group size is silly, as is the idea that 3 shot groups have zero correlation with larger groups. As I mentioned before, 3 shot groups are very good at weeding out bad loads, that was as true when I started loading as it is today. Overlapping multiple 3 shot groups provides the same final conformation that shooting ten all at once would.

In shooting, things are quite easy to prove or disprove - simply shoot it. Track the first three shots, then the second three on the same target, then the third three, and correlate it to overall group size. It shouldn’t take a podcast to tell someone if it works or doesn’t work. In my experience it’s hard to tell anything with inaccurate rifles, but it works just fine with accurate ones.

The same goes for all questions in reloading - simply shoot it. Comparing two close loads with different case prep, primers, powder, bullets, seating depth, or whatnot to determine which is best obviously requires larger groups than 3 shots.

What you’ve said isn’t necessarily wrong, and many folks benefit from the Hornady guys, but it simply doesn’t apply as universally as it may seem on the surface.

 

[Packmansion]

Even the Hornady guys have said that their stance on nodes is for the average reloader and is not applicable to all forms of shooting. The entire industry built around accuracy raked them over the coals for it. Nodes win matches.

The idea that powder charge has no influence on group size is silly, as is the idea that 3 shot groups have zero correlation with larger groups. As I mentioned before, 3 shot groups are very good at weeding out bad loads, that was as true when I started loading as it is today. Overlapping multiple 3 shot groups provides the same final conformation that shooting ten all at once would.

In shooting, things are quite easy to prove or disprove - simply shoot it. Track the first three shots, then the second three on the same target, then the third three, and correlate it to overall group size. It shouldn’t take a podcast to tell someone if it works or doesn’t work. In my experience it’s hard to tell anything with inaccurate rifles, but it works just fine with accurate ones.

The same goes for all questions in reloading - simply shoot it. Comparing two close loads with different case prep, primers, powder, bullets, seating depth, or whatnot to determine which is best obviously requires larger groups than 3 shots.

What you’ve said isn’t necessarily wrong, and many folks benefit from the Hornady guys, but it simply doesn’t apply as universally as it may seem on the surface.

The Hornady guys dont have a stance. They are presenting data. Will a grainof powder or .05 OAL change shrink your groups? sure it could. That's not really the main point. The main point is an ocw is a huge waste of time. Most people are not finding nodes, they are finding outliers within incomplete data sets. The way most people develop loads is basically the same as playing the roulette wheel. Load to desired velocity shoot a 10 shot group. If you are not in the ball park you need to change your powder or your bullet or maybe get a new gun. What I have said is 100% universal. Whether you're shooting a hunting rifle or prs gun if you want to know how accurate your rig is do a 30 shot group. Making a composite of 10 3 shot groups is just a round about way of making a 30 shot group. Just commit to the 30 shot group. I know the one Hornady guy recommended shooting like you would in your application and composite your groups but that is just more work for no benefit.