3 shot group vs ladder tests

[quest450]

ES/SD can vary for different reasons, I do my early testing at 300 yards, I’m basically looking for few consecutive chargers that group less than 1/2” at this point I pay no attention to es/sd let the paper tell you what the barrel likes or doesn’t

 

[Bc'z]

ES/SD can vary for different reasons, I do my early testing at 300 yards, I’m basically looking for few consecutive chargers that group less than 1/2” at this point I pay no attention to es/sd let the paper tell you what the barrel likes or doesn’t

View attachment 1680275

Beautiful target, it really shows the difference in what a tenth can do to a load.
Are you going to break 65-65.1 down into hundredths and reshoot?

 

[CharlieNC]

I’d be interested to hear what experienced shooters make of this target. Each group represents a 0.2 grain difference in powder charge. The center point of impact remains relatively consistent from group 2 to group 5. The test was conducted at 328 yards (300 meter). Red dot is 1/4 MOA.
View attachment 1680256 Look around 57.8, as 4-5 are flat at the top of the the trend for for vertical POI

 

[bsekf]

I have waded through most of this thread and if I was a new shooter I would be totally confused.

Virgil King of the Houston Warehouse made some interesting remarks about reloading. His secret was case prep.

I still like the Berger method of testing CBTO before you settle on a charge. But I do use ladders... sometimes. 10 shot groups are better the 5 shot groups are better than 3 shot groups. But one thing remains constant.

After the 2nd shot the group will never get smaller.

 

[KMW 1954]

After the 2nd shot the group will never get smaller.

I always get a kick out of that statement. It's akin to, "once born you are never going to get any younger!"

 

[Bottom Fodder]

Don’t over think it! You can make it way over complicated. All you’re looking far is group size that is acceptable to you and that will repeat! nothing says you can’t tweak that load later

 

[Bronsin]

As I said in my earlier post, and others have alluded to, a ladder of 3 shot groups will get you pointed in the right direction and save a lot of time and grief shooting loads that have no chance. I shoot SRBR, 1-200yds, with a couple at 300 mixed in. I finally got on top of my powder charges by doing a ladder at 300yds. I wanted to see what loads were still sprinting across the line, not limping there. Testing at 300yds isn't some magic. If I were competing at 600yds, then I would see what the load was doing at 800. I feel that testing at ranges beyond where you normally compete will show you that some of those loads that look like they might be good enough usually fall apart if forced to go farther, and you can rule them out as not being reliable.

I've heard all the sayings of "if it doesn't shoot at 100, it won't shoot further", and that is correct, however, just because it shoots at 100 doesn't mean it's going to be accurate at distance. If that were the case, everyone would be shooting the PPC regardless of the distance.

 

[Old Navy]

ES/SD can vary for different reasons, I do my early testing at 300 yards, I’m basically looking for few consecutive chargers that group less than 1/2” at this point I pay no attention to es/sd let the paper tell you what the barrel likes or doesn’t

View attachment 1680275

Good shooting.

 

[Ccrider]

ES/SD can vary for different reasons, I do my early testing at 300 yards, I’m basically looking for few consecutive chargers that group less than 1/2” at this point I pay no attention to es/sd let the paper tell you what the barrel likes or doesn’t

View attachment 1680275

So, how did 65 and 65.1 look at longer distance?

 

[209jones]

All this mathematical stuff is way too much mental gymnastics, too lazy to do it. I just shoot a picked load over a few days in different conditions to see how it holds up, does it move around or stay pretty much put, as to POI. I do min to max on a new gun with a new pound of powder because guns aren't all made perfect, some are screwed up, and powder isn't always perfect, sometimes some stuff gets out that shouldn't (which I've encountered). Maybe not the issue it was 30-45 yrs ago as to getting info out on powders, but, it spooked me enough that I always check min and work up. Manuals have been known to have mistakes too, Ed Matunas illustrated that. I check for top end load, whether or not I use it, depends on what I'm doing with the gun, 95% of the time I'm below that point by a grain or two, sometimes more. Lots of things get learned over time if you shoot enough, when you have something that is truly consistent, or not, can be pretty tough for a new guy that doesn't have the experience to see the telltales on it. Doesn't hurt to be aware of all the rabbit holes, what they can represent, or maybe even do for you, in helping a person understand what you see on paper, and maybe why or how you could have got there, or why what you have going on, will or won't help your hit percentage. Just have to remember that wind and conditions can negate all the effort you made, in a heartbeat, or in the case of competitions, a mental mistake, can easily be the difference between winnng or losing. And lots of folks expectations and applications don't really require all the fuss and bother us who do get into it, go thru. If I expend a few extra rounds to prove it out, so be it, won't be the end of the world, and I'll trust what is going on with my gun, then all I have to worry about, is me and the conditions.

 

[kyotekiller25]

I recommend running your “ladders” with three shot groups. Single shot ladders can be especially misleading. Two shot ladders may tell you what a barrel doesn’t like, but they won’t necessarily tell you what a barrel likes. You get more information about grouping, flat spots as well as how each of the charges “moves” shooting three shot “ladders”.

Remember, you aren’t looking for different charges that produce the same velocity. You are looking for points where the barrel harmonics and the velocity dump different charges into the same group(elevation).

Here is an old 1K three shot AA2495 ladder I shot when H4895 was in short supply. Two nodes were identified for this BRA barrel. Next step was a three shot test with a finer 1/10th grain increment. Sorry about the joke Roy!

View attachment 1674550

Things get tougher at 600 yards because shots start to cluster closer together, hopefully. Here is an old 600 yard ladder again with a BRA. Shortly after shooting this, the barrel, with 29.7 gr., shot the smallest 8 target aggregate ever shot at IBS Nationals. It was 1.611”

Notice the overlap of 29.7, 29.8 and 29.9. I like it when a lighter load prints on top of or preferably slightly higher than a heavier load. I will pick it every time. Sorry shot marker guys, but you really need a piece of paper in your hand to let it talk to you. It’s all about those triangles!

View attachment 1674551

Here is a seating “ladder”. I had a proven load with this 6.5x47L but was concerned about throat movement firing a 16 target match. The left to right wind kept picking up as I shot but you can see that .006” jump all the way up to .018” shot at about the same elevation so I had .012” of erosion to play with.

View attachment 1674553

This barrel and load ended up shooting a tiny 1.338” group at the Rendezvous three weeks later. The bottom line is three shot group “ladders” help me develop sound loads while minimizing round count. I then verify with 5 or ten shot groups depending on the match I’m tuning for.

View attachment 1674579

Dave.

What scope are you using at 1K to do load development? And usually what magnification?

 

[R.Morehouse]

I suggest getting the most magnification, highest quality scope you can afford.....You can always turn it down. I use a pre-Highmaster March 10-60, and it has never let me down.

Regards
Rick

 

[Ccrider]

Shooting a decent ppc at 100, two shot groups are almost useless. Same can be said for a 30br.

Three shot groups are hard to decipher if you do not know what to look for. The target below is from a ppc I am tuning at 100yds. 3/10 powder charge increment from left to right and 3/1000 I reduction in seating depth in second row. Two shot groups for all of them would have been zeros or low ones except for 1 group.

 

[Kracken McGraw]

Shooting a decent ppc at 100, two shot groups are almost useless. Same can be said for a 30br.

Three shot groups are hard to decipher if you do not know what to look for. The target below is from a ppc I am tuning at 100yds. 3/10 powder charge increment from left to right and 3/1000 I reduction in seating depth in second row. Two shot groups for all of them would have been zeros or low ones except for 1 group.


View attachment 1680967

You guys never fail to impress me in how you can make it all come together like this!

 

[Webster]

214 replies to figure out what a small group looks like. This subject has been covered a 100 times.

 

[Pete Wass]

If the second shot doesn't go into the first bullet hole, don't shoot the third Usually there are no surprises in the accuracy search. Buy powder known to work in the case you are using and make the process as simple as one can make it. Generally, don't expect miracles from a powder no one else is using. Once one has used a certain cartridge for a long time, the only thing to determine is what powder charge the barrel prefers. Don't waste components on a barrel "that WANTS to shoot", Move on.