For those who load test every way you can imagine...

[sbrabec]

I've have a few questions.... 1. Does it pay to vary seating depth and different powder weights together? I ladder test with different charge weights (all bullet depths the same), find the best vertical, then vary seating depth (all powder charges the same)?! 2. When we find a load that works, is it the weight of the charge thats perfect for that gun or the velocity that was produced under the testing conditions?
Thanks
Scott

 

[BoydAllen]

1. No
2. Probably both, but not necessarily the latter with just any combination of components.

 

[necchi]

1. No
2. Velocity, IMHO. As different temps can greatly change some powders, ie; winter/summer, the velocity being maintained by the charge variable makes or breaks the group,

 

[artbosco]

I've have a few questions.... 1. Does it pay to vary seating depth and different powder weights together?

Answer: No. I prefer a methodical approach such as this where each element is segregated:
Working Up a Load …. by Lee Euber

1. Polish bullet with steel wool. Initial seating depth achieved when bullet is marked by all lands. Tony Boyer likes to see a “square.” (Boyer's comments added for my reference.)

POWDER

2. Load 3 cases in a low grain load. Increase each 3 case load by .5 of a grain, and then shoot. Increase loads until primers show pressure.

3. Identify shots that grouped well, not so good, and then good again.

4. Pick load that shot the best. Load 3 cases with .1 grain less, and 3 with .1 grain more, for another comparison.

5. After picking charge for use, load 30 cases with the same powder charge.

SEATING DEPTH

6. Load the 30 cases in groups of 3, increasing the seating depth from touching the lands to jumping about .040 of an inch, in increments of .005 of an inch.

7. Shoot all 30 rounds without cleaning or clean after each 10.

8. Use ONE fouling shot after each cleaning.

9. Select load that shot best. Load 5 cases with that powder charge and seating depth.

10. Load 10 cases, 5 with seating depth .005 less than benchmark figure and 5 with .005 more.

11. Can compare more than once or change seating depth by .001 or .002.

12. Once you’ve picked the best seating depth, load 15 cases at that depth.

POWDER

13. Check first test by varying charge by .1 grain, for each 5 shot group.

14. Shoot in a medium wind condition, letting the gun do the work.

SEATING DEPTH

15. After picking the best load jumping the lands, compare it with the load that touches. Compare these loads again and again, on different days, in varying conditions, deciding which one is best.

16. If it doesn’t shoot to your satisfaction, restart with a different powder.

NECK TENSION

17. If you decide on the load that puts the bullet in the lands, be sure neck tension is tight enough to hold the bullet uniformly.


2. When we find a load that works, is it the weight of the charge that's perfect for that gun or the velocity that was produced under the testing conditions?

Answer: It was all the above used in the tune that made the difference in the barrel's tune. Velocity is just a byproduct. In other words you don't tune with velocity, but you can record the tune's velocity for whatever it's worth, for example, for statistical purposes.

 

[NorCalMikie]

All you'll get by changing the powder charge and the seating depth at the same time is a "real bad" headache!! You'll end up chasing your tail trying to figure out what change made the difference, the powder charge or the seating depth. (been there, done that :-[) If the shots are going in the same hole, or real close, that's the bottom line. After you get the rounds to group the way you want them, then start checking the speed. Change the powder charge and watch your groups go all over the place. You don't have to be fast to be accurate. A bug hole is a bug hole, no matter how fast the bullet gets there.

 

[sbrabec]

One more question... Last time I ladder tested some loads, I forgot my chronograph. Is it safe to say that the loads with the least vertical also have low SD, ES?

And just to clarify, the reason I asked about the weight of the charge or velocity was, as NECCHI stated, temp changes and powder sensitivity.????

Thanks guys
Scott

 

[necchi]

Check this out,
http://optimalchargeweight.embarqspace.com/

You can leave the chrony home until you need it. You need to get close to what you want Before you do the fine tuning.
Worrying about ES and SD when doing a ladder or OCW test is IMO putting the cart in front of the horse. Let's do step 1 before we move to step 5. ;D

 

[40X Guy]

+ 1 on the OCW Optimum Charge Weight test. That will get it done.

Frank

 

[necchi]

sbrabec,
this topic of temps and powders has been done a couple time with interesting and varied opinion. Check out this kinda current thread,,and be sure to click the link provided by RonAKA;
http://www.accurateshooter.com/forum/index.php/topic,3755328.0.html

 

[ReedG]

I start my load testing by seating all bullets .005 off the lands and loading 3 each at different powder weights. This is done with several bullets and several powders. Whichever loads show the most concentric and, hopefully, smallest groups I then load 3 each of that load in .005 steps from -.010 to +.010. When that is done you will usually have the best load for that bullet.

If the group is small and concentric, I don't care what the ES or SD is!

 

[deadlyswift]

Have you read this Article? This is a awesome ladder test. It well work at any distance. I suggest going out to at least 300yrds. So that you can clearly see the vertical on the target. This does work and works very well. I use it with just about all my load development. As others have said only change 1 thing at a time.

http://www.accurateshooter.com/technical-articles/long-range-load-development/