Ladder test result ????

[Silverback]

I thought that I might as well try a ladder test at 300 metres with my 338 Lapua with a new powder/bullet combination, I'm not sure that the results are that good. I went up in one grain increments and I let the rifle cool between shots, making sure that the rifle was level for each shot and all shots felt good with no perceived flyers. I might have to retry the 85-91 grain loads. Action screws were torqued down but it is not bedded yet. Any thoughts?

 

[scout]

You might want to try 1/2 grain increments, going 4 grains down from what you might have found as a max load with the 1 grain increments. Can you comment on your front and rear rests and the surface you shot off of?

 

[horseman2]

You are pretty close but that 85 is really out of the test.
What velocities were you striving for? Where are the loads in respect to maximum (which might explain 92 trying to escape).
The bullet, primer, brass and powder might offer clues to those who have ladder tested.

 

[Silverback]

You might want to try 1/2 grain increments, going 4 grains down from what you might have found as a max load with the 1 grain increments. Can you comment on your front and rear rests and the surface you shot off of?

I use a Caldwell Rock BR front rest and a rabbit ear rear bag shot off a steel framed bench sitting on concrete, wind was very light.

You are pretty close but that 85 is really out of the test.
What velocities were you striving for? Where are the loads in respect to maximum (which might explain 92 trying to escape).
The bullet, primer, brass and powder might offer clues to those who have ladder tested.

I am going for accuracy more than any set velocity, 92 is roughly the book maximum with this powder.
I was using 300 gr. Berger Match Hybrid OTM Tactical, Federal GM215M primer, Lapua brass, VV N570 powder.

 

[cr5]

I use a Caldwell Rock BR front rest and a rabbit ear rear bag shot off a steel framed bench sitting on concrete, wind was very light.

I am going for accuracy more than any set velocity, 92 is roughly the book maximum with this powder.
I was using 300 gr. Berger Match Hybrid OTM Tactical, Federal GM215M primer, Lapua brass, VV N570 powder.

Sounds like you have all the right components. What kind of jump to the lands are you loading to?
I was having a heck of a time getting those bullets to shoot well until I ran them almost touching the lands. They seem to be very sensitive to seating depth and do best with only a couple thou jump.
I have some more testers built to confirm my load then I'm hoping to be finished with development on the 338. Problem is that I'm using US869 and my buddy suggested I switch to a more temp stable powder (he uses N570). I really don't want to start over again.

 

[Mystic Precision]

Consider the load tuning info on my website.... see Tech section.

I do not like ladder testing as you have done. WAY too much opportunity to get bad data.

My version is a simple variation and it works....

Good luck.

Jerry

 

[Silverback]

Sounds like you have all the right components. What kind of jump to the lands are you loading to?
I was having a heck of a time getting those bullets to shoot well until I ran them almost touching the lands. They seem to be very sensitive to seating depth and do best with only a couple thou jump.
I have some more testers built to confirm my load then I'm hoping to be finished with development on the 338. Problem is that I'm using US869 and my buddy suggested I switch to a more temp stable powder (he uses N570). I really don't want to start over again.

I had 0.020" jump. I'll have to try closer.

 

[Silverback]

Consider the load tuning info on my website.... see Tech section.

I do not like ladder testing as you have done. WAY too much opportunity to get bad data.

My version is a simple variation and it works....

Good luck.

Jerry

I'll check it out Jerry, thanks. This is the first time I tried the ladder test, just wanted to see what I would get from it.