OCW/Ladder/Other - load development

[Prerylyon]

Anyone use 'optimal charge weight', 'ladder' , (mix of the 2) or maybe some other method to work up an accurate load for your rifle?

Fair bit of debate in many forums over the years on the merits of the OCW vs Ladder; curious about other members experiences with these methods for load development.

Regards,

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[rammont]

I tend to use the OCW process but the ladder test is good too, just more suited to long range testing.

 

[Prerylyon]

In reading discussions on both, it strikes me that a hybrid approach, using both, might be worthwhile if a guy really wanted to see what was possible? Like do OCW, then use a ladder experiments centered around what you learned from your OCW load tests?

I've never done anything quite as methodical as either; the concepts appealed to me, the rationales, science, logic, seemed sound.

All I've ever done is cook up rounds to a recipe and see which ones grouped the best, of the fastest I got that showed no pressure signs.

As hunter shooting out to maybe 300+ yards at most, maybe I don't need to be so analytical about it?

Regards,




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[Bonecollector]

Prerylyon- We're guys, that's why we do it!

 

[Bonecollector]

Just to through up some data since were both feeding .284 tubes (.280 & 7mag)
I worked up three loads of (3) with the 145 grain Barnes LRX yesterday.
Seated .050" off the lands with H100, Alliant 23, & Alliant 26. All loads were at about 80% of recommended max charge.
Groups at 100 yards:
H1000 was .90" Slowest group -200 f/s
A-23 was 7/16" Fastest group
A-26 was 3/16" -75 f/s

My plan is to do a few more tests with the A23 & A26 closer to max charge at a longer distance target.

Question: how much does moving to/fro the lands actual affect bullet accuracy? Does it affect speed much? Hard to imagine moving from .050" to .055" having much affect, but apparently it does, but simply so hard to imagine since it's such a finite measurement.

On another note: I was able to recover one of the bullets after digging it out of the ground. It performed as advertised (even going into the ground as opposed to an animal). The retained weight was 128g of 145g for 88% weight retention. I feel that is very good considering the backstop.

I always have a lot of fun doing these tests.

 

[Prerylyon]

That retained weight is pretty interesting. While not an animal, good to see it did its job into some tough stuff.

Regards,

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[Prerylyon]

My dilemma messing with OCW for what I got right now:

The published load recipe has only a 2 gr spread between starting load and max. The powder is RL-19. 55 to 57gr.

Seems like that spread is a little tight to really apply OCW. Idk. Maybe the engineers/ballisticians at Speer are just good and its a forgiving recipe. We shall find out.

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[Colorado Cowboy]

Damn guys, I don't want to sound stupid, but I've been reloading for over 60 years and don't know what the hell you are talking about! OCW.... ladder test?

 

[Prerylyon]

Oh, its just "stuff" lol

Don't feel bad, I have been reloading for only 5 yrs and I didn't know about them either. lol (just kidding! )

I found guys talking about these methods in a bunch of shooting forums and in some shooting magazine articles. They're processes based on some ballistics principles to help fine tune a specific load to a specific barrel for accuracy. Apparently some of the science goes way back; to how they calibrated loads for navy artillery.

There's lots of stuff online on both methods, if you google 'ocw optimal charge weight' or 'rifle ladder test reload'

This is a website that a gentleman who worked a lot on, and captured the OCW method as a process, has:

http://optimalchargeweight.embarqspace.com/ocw-instructions/4529817134

Like anything online, there are some ridiculously heated threads in different forums where guys argue about the better of the two methods.

That is not at all my intent here. More just to discuss these methods from a big game hunting perspective, as to how they may be applied to reloading.

Regards,

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[Colorado Cowboy]

When I develop a load for a new gun, I generally look at the ballistics and recommended powder in various manuals. I have my favorite powders and bullets so I usually start out with them. I pick mid range on the powder charge and load 3 rounds batches increasing powder charge by 1/2 grain per batch. Use my Chrono and record velocity of every round shot. I can usually find the tightest group and that is what I load for more testing at various ranges. Used this methodology for years.

 

[rammont]

OCW (optimum charge weight) and the Ladder test are just systems you can use to try to find a powder charge that gives you the most reliable group size, maybe not the smallest but the most repeatable. The idea is that if you can get a powder charge that reliably produces the same size group over the greatest variation in conditions then you'll have a load that works well in most any situation.

The OCW test process has you shoot a series of round robin style groups, 3 to 5 shots in a group and as many groups as powder charges you want to test. You are supposed to fire one round for each powder charge at it's appropriate target across the powder charge range that you are testing and then you fire a second round from each powder charge group at their appropriate target and you do that over and over until all the rounds are fired. The round robin style process is supposed to remove any man made influence on the test results. The objective being to find a powder charge that produces a series of groups that are all centered in the same place over several targets, you pick the powder charge in the middle of that series and you have the OCW charge.

The Ladder test process has you shoot a series of shots (each cartridge having a different powder charge) at mid range targets (preferably 2 or 3 hundred yards) with the expectation of finding several powder charges that put a few impacts close together which, theoretically, finds a powder charge that will perform very reliably because it's in the center of a group of charges that perform very similarly.

They are just more tools in the box that can help you find a load that you have confidence in.

 

[rammont]

In reading discussions on both, it strikes me that a hybrid approach, using both, might be worthwhile if a guy really wanted to see what was possible? Like do OCW, then use a ladder experiments centered around what you learned from your OCW load tests?

I've never done anything quite as methodical as either; the concepts appealed to me, the rationales, science, logic, seemed sound.

All I've ever done is cook up rounds to a recipe and see which ones grouped the best, of the fastest I got that showed no pressure signs.

As hunter shooting out to maybe 300+ yards at most, maybe I don't need to be so analytical about it?

Regards,




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When I do my group testing I just use the OCW test since it's basically the same as shooting test groups except you shoot one cartridge from each powder charge at it's designated target. I buy targets with at least 6 bull's eyes and then load up a specific powder charge weight for each bull's eye. I always test the load I pick with a standard 3 or 5 round group test depending on how my reloading supplies are holding up or the kind of shooting I intend to do with that cartridge.

I don't see how you could combine the tests unless you used one test to narrow the range of powder charges and then the other test to make a final choice. But then you'd have to make a choice about which test was better for a course filter of charge weights and which was better for a fine tune and I don't think one is proven to any better than the other. I can say that the OCW will use more rounds to complete a test while the ladder test requires longer ranges to conduct.

 

[JimP]

I'm old school and do exactly like CC does.

I have been lucky in that I havn't had to buy a lot of different powders to find my loads. I go over the manuals and see how fast I want my bullet to go and then work up it that charge and velocity. If I start to see pressure signs I'll see if I can use a powder that gives me the velocity that I want well below it's maximum loading.

This has worked out for me quite well in the 50 years that I have been reloading.

 

[rammont]

I've been reloading since the 1970's but I'm one of those old dogs that likes to try out new things, sometimes new tricks actually do work. I also use QuickLoad software and have read just about everything I could find on bullet aerodynamics and ballistics theory. I've always enjoyed researching why things do what they do so I tend to be really detail oriented. It doesn't make me any better of a shooter but it's fun and sometimes I can make rifles do things that most people think is impossible (sub-MOA M!A SOCOM).