shinbone
Well-Known Member
Thanks. They are very easy to do in Excell. For me, a visual representation of results is helpful when comparing across multiple bullets and powders, especially months after the data was collected.
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Help a gal with load development-seating depth
- Thread starter Mram10us
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Thanks. They are very easy to do in Excell. For me, a visual representation of results is helpful when comparing across multiple bullets and powders, especially months after the data was collected.
codyadams
Well-Known Member
I use the graphs as well for finding flat spots in velocity. They work well, and also help me keep track of loading history, it is saved in my google drive and wont get lost, and is easy to refer back to.
Wolf76
Well-Known Member
Since seating depth is a bit of trial and error, I generally move 15 thousandths increments. Then fine tune in .005 increments. Don't think I've ever tried smaller increments than that. Maybe I'm totally missing the boat. My hunting guns consistently shoot an honest 5/8" or better.
BUT- if you need to shoot .1"groups, it might be worth the extra a effort. I can't say below .5moa is worth it to me.
BUT- if you need to shoot .1"groups, it might be worth the extra a effort. I can't say below .5moa is worth it to me.
http://optimalchargeweight.embarqspace.com/
I use Dan's method. It conserves throats and makes a fast, effective result. I do the same thing with seating depth/length in 0.020" increments. If I can't get a result at twenty thou jumps, I can cut back to five or ten. Or one. But I think you will find that a .01 grain or even a .1 grain powder charge difference is negligible just as a .001 or .002 length difference will be. Heck, a lot of hp long range hunting bullets have .010 length differences, which is why we use bore diameter comparators instead of measuring case overall length.
My goal is quick load optimization, fewer trips testing at the range means more time shooting. Fewer holes in paper means more steel or flesh pounded in the field. And more throat life left for doing what I bought a gun for: shooting stuff!
I guess I don't see how it conserves the throat. Fire erodes the throat which means every shot erodes it. Doesn't ocw use 3 shot groups?
Troutslayer2
Well-Known Member
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- May 28, 2010
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I recently worked up a new load and started as usual .015 off. I was getting great es and sd but things just weren't coming together with group size, played around in .010 increments, didn't really get the results I was after. I consulted Nosler's web page/forum and found out that they were recommending .075 jump which seems like a mile to me. Tried it and immediately cut my groups down to 1/2 MOA.
I think most manufacturers have a pretty good idea on how to use their product and if I had listened to them in the first place it might have saved some components.
I think most manufacturers have a pretty good idea on how to use their product and if I had listened to them in the first place it might have saved some components.
Fewer shots. Quick and dirty. Only not dirty.
I have been successful with some oddball rounds just doing one shot steps too.
Mikecr
Well-Known Member
OCW is about finding the most tolerant load, not the most accurate.
That may or may not be what you want, so keep this in mind.
That may or may not be what you want, so keep this in mind.
Tolerant vs accurate? Please explain. I've always been after accuracy and the audette method gets me there quickly. Just need to fine tune the seating depth without blowing through 50 rounds. Seems that 3-5 rounds every .015" to find a rough measurement then fine tune from there is the consensus
Memberberries
Well-Known Member
Here is how I understand it
Most Accurate is "closest to what I aimed at" and is what you learn from one shot steps on a ladder test. It will reflect how close this load is to a standard or what you zero your scope with.
Most Precise is "smallest group size" but this tiny group might not be located near your current point of aim and require that you re-zero your rifle. This is obtained from shooting groups and picking the smallest one on the target.
Most Tolerant is "shots of this load are least sensitive to minor deviations in my loading" and this is what Audette's method is quite good at identifying. This method needs a chronograph and works quite well with excel or some other data analysis tool but you can do it on graph paper.
My personal preference is a ladder test where I shoot 3 shot groups at each step (usually 15 or less unless its a brand new gun/powder/caliber to me). I then take the group size and the velocity measurements and put them in Excel, refine, and repeat.
Most Accurate is "closest to what I aimed at" and is what you learn from one shot steps on a ladder test. It will reflect how close this load is to a standard or what you zero your scope with.
Most Precise is "smallest group size" but this tiny group might not be located near your current point of aim and require that you re-zero your rifle. This is obtained from shooting groups and picking the smallest one on the target.
Most Tolerant is "shots of this load are least sensitive to minor deviations in my loading" and this is what Audette's method is quite good at identifying. This method needs a chronograph and works quite well with excel or some other data analysis tool but you can do it on graph paper.
My personal preference is a ladder test where I shoot 3 shot groups at each step (usually 15 or less unless its a brand new gun/powder/caliber to me). I then take the group size and the velocity measurements and put them in Excel, refine, and repeat.
MB, sounds good. I don't agree that the CA ladder method needs a chrono but everything else sounds good.
For perspective, I've never once messed with seating depth during load development. I start somewhere between 20-30 thou off the lands and I've always gotten a consistent load that shoots sub 1/2 MOA. It's not to be or sound arrogant but components (both rifle and reloading) matter. Fretting over better is also, in the grand scheme of things, relatively trivial. Put everything in your favor to develop a consistent load and you should be successful. Bullets that have a reputation for not being finicky. High quality consistent brass. Temperature insensitive powders. Precise reloading practices. Etc.
Also, for a hunting rifle you don't want to be in the lands. If you've ever had a bullet that was jammed and then was pulled on opening the bolt, subsequently spilling powder everywhere you know what I mean. That blows. It can also create issues with loading into a magazine.
I have adjusted seating depth to get back and chase the lands, but literally have never had to do a seating depth test to get a load to shoot...maybe I've just been fortunate. It's not to say that it might not be necessary but it seems like it's not necessary most of the time.
Also, for a hunting rifle you don't want to be in the lands. If you've ever had a bullet that was jammed and then was pulled on opening the bolt, subsequently spilling powder everywhere you know what I mean. That blows. It can also create issues with loading into a magazine.
I have adjusted seating depth to get back and chase the lands, but literally have never had to do a seating depth test to get a load to shoot...maybe I've just been fortunate. It's not to say that it might not be necessary but it seems like it's not necessary most of the time.
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codyadams
Well-Known Member
It doesn't NEED a chrono, but it can help double check things. If the velocities correspond with the impacts that is good. However if you have an impact that doesnt, outside factors may have come into play. I have had mirage move my target several inches in my scope at distance, and thought I was aiming center but really wasn't, and when you are measuring inches on a ladder target, it can be affected. This is just one example. You are correct, a chrono is not needed for a ladder, but it can certainly help at times.
Memberberries
Well-Known Member
I will agree with both of you that a Chrono is not absolutely necessary for a CA ladder test but it certainly makes for better data.
Everyone has their own preference for jump and I agree that touching the lands is not mine for a hunting load. Those benchrest guys that use the lands to finish seating the bullet have a different opinion though.
Everyone has their own preference for jump and I agree that touching the lands is not mine for a hunting load. Those benchrest guys that use the lands to finish seating the bullet have a different opinion though.
