OCW vs Ladder vs Chronograph

[daniel brothers]

What's the Goal with any of these test... it's controlling the barrel harmonics to it's Maximum Stabilization. A barrel that is 2 inch in diameter will stabilize quicker than a Sporter dia barrel.
The Skinner the barrel... the more testing is needed to stabilize it. A stabilized barrel is one that will shoot with A LOT of forgiveness, even when the powder loads are not exactly the same each time. Finding that Node is the Goal... in my opinion. A barrel whipping around is no fun to shoot at all, only frustrating. After spending thousands of dollars on a rifle, scope, and quality reloading components... I sure don't mind spending a extra hundred bucks... while investing a few more hours of time into the over all package deal of building and creating a pleasurable shooting rig.

Why buy that new car or boat if your worried about the time and gas money to drive them around.

Reloading is not about saving money or time, and that should be the very last thing to skimp on.... it's about building accuracy.

 

[Toby Bradshaw]

Load development by any method is easy if the rifle is very accurate, and difficult/time-consuming/unsatisfying otherwise. With an accurate rifle, the POI of even a single shot is very informative. In a benchrest rifle a half-bullet-hole displacement at 100 yards means something. With a 1 MOA rifle a much larger displacement of 1/2"-3/4" is meaningless, so it takes more shots to figure out where the less-accurate rifle is really impacting.

My hunting rifles are shot from field positions, may use bullets (e.g., monolithics, varmint bullets) that aren't optimum for accuracy but provide the desired terminal performance, and generally are chambered for barrel-burning cartridges, so I do a simple ladder (as shown in post #3 in this thread) because absolute ultimate accuracy is not required when it comes at the expense of barrel life. Good enough is good enough. For me, a 0.5 MOA hunting rifle is adequate for any shooting that I do under field conditions. If the rifle shoots worse than that I send it down the road, which is why I have almost no factory rifles in the safe anymore.

For competitive shooting at 100-300 yards I generally use the method described in Tony Boyer's book, with a factorial combination of 3 powder charges and ~4 seating depths, fired in 3-shot groups at 100 yards, and not holding for wind. On the 30BR target below ANY of these loads would easily meet my hunting criterion, but if you are familiar with how group size and shape change with charge and seating depth there is a clear pattern and an obvious choice for competition. I shot the charge/depth combo determined from this test out to 300 yards and was not disappointed.

 

[Jennb]

I personally like to find my charge weight through the chronograph for two reasons. I can use the chronograph at home and wind has no effect on the information since it is attached to my barrel. Once I find my charge then I fine tune with a seating depth test at the range at 300 yards without the chronograph.

There are many different ways to accomplish the same thing.

 

[gman47564]

do both.. do a velocity ladder and a ocw to confirm the velocity ladder or vice versa... its shooting and we all like to shoot.... might as well learn while were doing it

 

[daniel brothers]

Toby.... good target...... it looks like seating depth was more important than the powder charge.

 

[Brians356]

For competitive shooting at 100-300 yards I generally use the method described in Tony Boyer's book, with a factorial combination of 3 powder charges and ~4 seating depths, fired in 3-shot groups at 100 yards, and not holding for wind.

Is it safe to deduce there wasn't much wind to hold off for?
-

 

[Adam in WI]

One thing I'm noticing here is not much representation for the chronograph method. I guess I was hoping there would've been more shooters relay positive experience with this method, if nothing more than for practical reasons. It's easy to set up and read a dozen shots over the magneto, even if the wind is not co operating or even if it's dark outside. It's tough sometimes to get enough time to run a couple dozen shots on target with favorable conditions.

 

[Bindi2]

I use a chronograph to find the velocity the barrel likes with the components selected adjust the tuner for best group at 100 adjust scope to zeros then go to 300 check and adjust tuner, repeat at 600 then again at 900 don't have 1000yds. Have found that the 900 sets will not shoot at 600 or closer and the 100/300 sets fail by 700. I do not change my seating depth the barrel has already told me what it likes. The wind is no concern as long as it is constant, better if zero but low is OK. There seems to be a divide at the 600/700 distance. I shoot from 300 to 1000 by 100 increments. No two barrels are the same. I am using two 30 cal barrels that have two grains difference for the same velocity window. The 7mms are very close to being the same but the divide is a bigger cliff fall.

 

[Toby Bradshaw]

Is it safe to deduce there wasn't much wind to hold off for?
-

Not calm but not bad, and relatively steady.

 

[gman47564]

The 10 shot velocity ladder is all i ever use anymore.. i load for about a dozen different calibers and i must just be lucky because I've got 1/2 moa or better loads for all of them and better than that for a few of them.. i use to do ocw test to verify what i was seeing with the ladder but they always showed the same nodes.. lots of ways to skin this cat.. best to find what works for ourselves..

 

[JFrank]

Additionally I’ll point out that no matter how or whatever method a person chooses to develop a quality product, during the life of the barrel there will be tuning again and again. Every serious competitor that I know tunes and tests prior to a sanction event.
So just to say - I only use x number of rounds to get there and my system is better then the other xxx Well that’s only part of the story...
J

 

[Bindi2]

When a bullet/cartridge/powder combo starts reaching maximum+ pressure and load density, of course it starts becoming consistent. Trouble is, by then you are right next to the area where it gets really spikey and dangerous.

Please explain why in this situation a load I was trying to develop would not come within 50 fps ES at pressure signs. Changed the primer to a hotter one bingo single digit ES with higher velocity at slightly less powder but close to max density. I do use a drop tube but do not compress loads. I consider the chronograph a very good tool in the path to accuracy, there are others but none as cold hearted as the chronograph.

 

[Jarhead6870]

I think using a method you have confidence and success with, based on your purpose/goals, to methodically determine what will shoot well in your rifle goes a long way in building confidence in one's shooting. Knowing you have a good rifle, good fundamentals and a good load leaves only your ability to read the wind to determine your success.

This said, I also don't believe in chasing the "perfect" load as there are too many combinations of powder, bullets, primers and powders; if a load shoots to my needs, I call it good.

 

[Depart123]

Please explain why in this situation a load I was trying to develop would not come within 50 fps ES at pressure signs. Changed the primer to a hotter one bingo single digit ES with higher velocity at slightly less powder but close to max density. I do use a drop tube but do not compress loads. I consider the chronograph a very good tool in the path to accuracy, there are others but none as cold hearted as the chronograph.

So you found a primer that ignited your powder more efficiently, not sure there is any mystery there. You confirmed it by chronograph, no mystery there either.

 

[CharlieNC]

For those of you who switched from targets to Chrono, I would love to see a direct comparison which convinced you to change. I assume a target is still used to evaluate seating depth?

 

[Bindi2]

So you found a primer that ignited your powder more efficiently, not sure there is any mystery there. You confirmed it by chronograph, no mystery there either.

The first load did not come together before it went over the top.

 

[Bindi2]

For those of you who switched from targets to Chrono, I would love to see a direct comparison which convinced you to change. I assume a target is still used to evaluate seating depth?

I don't change my seating depth from the first shot only the tuner after the barrel tells me what it likes as velocity ES (single digits)

 

[Adam in WI]

I don't change my seating depth from the first shot only the tuner after the barrel tells me what it likes as velocity ES (single digits)

How many rounds do you run before settling on a charge? Do you do the 10 shot method or are you running multiple rounds of each increment?

 

[Bindi2]

How many rounds do you run before settling on a charge? Do you do the 10 shot method or are you running multiple rounds of each increment?[/QUOTE

3 rounds on each increment to find a low or fairly flat increase in velocity. I like single digit climb but low teens is ok. .2 increments... The wider the window the better 1gn best .6 minimum then go back to the middle and down .1 and up .1.. But have been known just to go to the middle and tune if the fps are low teens then some singles then back to low teens

 

[BartsBullets]

Hummmm.....I tune by shooting 3 Shot groups at 100 yards. I use the Chronograph to determine how much change in velocity the barrel can take. I don’t shoot ladders and I can read wind flags so no need to shoot OCW.

Before you tell me that won’t work for 600 and 1000 yard matches. Probably best to check the match results first.

Bart