Ladder test interpretation

[cahunter805]

I’d load up 20 at 75.4 (#9) and see how they group.

If it’s crap, back off another ~ .5 grain.

This is what I would try also.
Magnum works great in the 257Wby in my experience. So does H1000.

 

[mevertsen]

Here's my thoughts.

I've been reloading for 20 years.

I have not reloaded a magnum cartridge.

My largest is .30-06.

Obviously, it seems you are dealing with a new gun, but it appears it handles pressure fine. Some guns will show pressure early. (I have to be a bit conservative with my .223 single shot and .30-30).

For my .223, .300 BLK, .30-30, .243 I load in .5 grain increments when testing for pressure.
For my .30-06, I load in 1 grain increments (IMR and H4350), .5 with IMR4895.
For my PISTOLS, I load in .3 grain increments with FAST powder.

I load in groups of 3, 1 for pressure, then 2 for at least an initial group, after checking pressure. I start at the MAX listed charge, go down about 7 to 10 percent and divide it up there. My pressure ladders will only be about 5 rounds.

The trend for me loading that way usually means by the time I am near the top; I know two things.

a. Where is my max? Or is the max load safe?
b. As I go up, those two shot groups should start getting closer to each other, or at least, I'll have a real good idea.

I will also see clear differences in primers, sooting, etc.

I run the single pressure (often without a speed), then check the "group" with the other two rounds. One thing at a time.

When I find something promising, I will then load a few more, check velocity and a 3 or 5 shot group to confirm.

I want all this done in less than 20 shots. If I can't even get close with that, I'm wasting time.

Now, for your .257 Bee?

I'm going down from max in 1 grain increments.

15 shots. 5 to find pressure, and 2 to get an idea on accuracy. Its obvious your gun...

a. is ok with higher pressure loads, so as long as you're not going out in to truly no man's land, experimental bullets, data that isn't available, etc., I would be comfortable with that latter.

b. your gun is reasonably accurate, so space your charges out a bit to see a difference

You are burning a metric shit ton of powder. Your tests are so close in powder wise, you are almost in the area of error on any individual component. The percentages are so small, you are just wasting time and energy.

My bet is if you space things out a little, you will see better patterns.

Good luck.

 

[Wind Gypsy]

Data I am using went up to 77gr but that was off coal of 3.417”. I am at 3.389”.

Who's data is that?

 

[Fire_9]

If you're not seeing pressure signs, load 10-15 at 75 or 76 and see what you get for accuracy and velocity. Loading one round at each charge is a waste of time in my opinion. I know some guys like it but it's just not enough data

 

[TheJason]

Personally I’d look at a different powder.

 

[yakimanoob]

Your main problem is that ladder tests are hot garbage in the first place; don't waste your time and $$.

Load up 3-5 rounds in a middle-of-the-road charge. If you don't hate the accuracy, then start creeping up in charge weight to get to the velocity you want, understanding that other things being equal charge weight only determines velocity, NOT accuracy/group size. If you do hate the accuracy, then change powders or bullets, rinse, and repeat.

Based on the closest Hodgdon data I can readily find, Magnum in the 257 Wby with 115gr bullets should give you something like 50fps more for each grain of additional powder on average within the range of book values. However, I'm with the other folks on noting you're outside of typical book values anyway, so it's a little hard to take educated guesses on what your velocity should be. That said, the data you got (graphed below) does seem remarkably flat. Maybe it's a statistical anomaly, but it does seem odd.

Long story short, you're either in the wrong range for Magnum, or your rifle doesn't like the Magnum/110AB combo in the first place, or both.

Cheers,

 

[VikingsGuy]

Velocity ladders are great way to work up loads quickly. Something seems off on this one - Wrong powder? Wrong range? Problem with powder scale? Wrong bullet? I would try again with a different powder and work up from the median loading book load up to max load. I would also check the powder scale. I would expect a more typical result next time around.

 

[golfer]

Velocity ladders are great way to work up loads quickly. Something seems off on this one - Wrong powder? Wrong range? Problem with powder scale? Wrong bullet? I would try again with a different powder and work up from the median loading book load up to max load. I would also check the powder scale. I would expect a more typical result next time around.

Leaning more that maybe it’s the powder. I had other loads measured out on that scale increasing in charge weights and velocity was what you would expect with increasing charges.

 

[VikingsGuy]

Leaning more that maybe it’s the powder. I had other loads measured out on that scale increasing in charge weights and velocity was what you would expect with increasing charges.

What reloading book you using?

 

[Redmt]

This has been an interesting discussion. What do you all say that the biggest impact on accuracy development to be?

 

[elkantlers]

This has been an interesting discussion. What do you all say that the biggest impact on accuracy development to be?

Me. lol

I think people put too much emphasis on velocity.

 

[Redmt]

Me

Positive or negative?

 

[elkantlers]

Definitely negative.

 

[yakimanoob]

This has been an interesting discussion. What do you all say that the biggest impact on accuracy development to be?

The bullet-powder combination is king. There is ample evidence that presumed differences in accuracy seen in small-sample methods (e.g. latter tests, OCW, etc) disappear if you keep shooting. In other words, jump/COAL and charge weight have negligible effects on accuracy.

 

[Redmt]

The bullet-powder combination is king. There is ample evidence that presumed differences in accuracy seen in small-sample methods (e.g. latter tests, OCW, etc) disappear if you keep shooting. In other words, jump/COAL and charge weight have negligible effects on accuracy.

Ok, in that case why would a proven load be great in one rifle and not another? I have a fantastic load for a Ruger Predator and it sucks for my Ruger #1 of the same caliber. All of the reloads were from the same batch.

 

[95tigerbill]

I question the lab radar - not the unit itself but maybe the setup/angle etc. without repeat measurements with same load it is hard to judge the results.

 

[yakimanoob]

Ok, in that case why would a proven load be great in one rifle and not another? I have a fantastic load for a Ruger Predator and it sucks for my Ruger #1 of the same caliber. All of the reloads were from the same batch.

Apologies; I meant that for a given rifle, the bullet-powder combo is king. So the rifle-bullet-powder combination, to be more specific.