Wanted to Share a Ladder

[USMCDOC]

Here is a ladder test i did today:

223 ISSF reamer, lands are at 2.0535 (base to ogive), base to datum (using an older Stoney point) is 1.4495 on a fired case.
Lapua brass, sized to 1.4485 base to datum, neck is at .2495 (no turn)
Berger 90 VLD, seated .005 off the lands
Wolf primer
i began at 23.5 and finished with 25.0 of RL15



I have an idea where i want to be looking at, i am wondering how many of you would concur with my thinking!

 

[Regnar]

23.9 - 24.3?

 

[wedgy]

What distance ? Just asking because it tends to make it more clear the further out I go. I also have been using Labradar chrono data along with the ladder. What is the intended purpose of the gun ? Are you looking for longevity or a hunting load ? Some of the things that influence my choices.
Am I missing 24.8 ?

 

[USMCDOC]

What distance ? Just asking because it tends to make it more clear the further out I go. I also have been using Labradar chrono data along with the ladder. What is the intended purpose of the gun ? Are you looking for longevity or a hunting load ? Some of the things that influence my choices.
Am I missing 24.8 ?

Yes.. now that you mention it.. i booboo'd on that.. let me make that correction!



i screwed up there.. but now it is right.. went back and looked at the sheet where i did the test

That is two bullets in the same hole where i originally had written 24.0 & 24.1

 

[USMCDOC]

23.9 - 24.3?

Actually, i am looking at the 24.4 & 24.5

Can't look at the 23.9 - 24.3 due to the huge jump in the ladder from 24.2 to the 24.3,
but i guess one could look at the 23.9 - 24.1

 

[USMCDOC]

What distance?

Sorry.. almost forgot to allow that to ya! it was shot at 300 yards

 

[eric n]

I've had some batches that would cut that .2495 neck pretty close w/o turning. I see .013 quite often with lapua. Something to be aware of....

 

[USMCDOC]

I've had some batches that would cut that .2495 neck pretty close w/o turning. I see .013 quite often with lapua. Something to be aware of....

Chamber neck is .2515, so yes.. it is close..

 

[wedgy]

OK you corrected that whatever it was into the 24.8(the one out left)

 

[eric n]

Chamber neck is .2515, so yes.. it is close..

Ahh yes, I misread it. Thought your reamer was spec'd at .2495
Just curious,did you spec it at .2515? Mine is a little larger and was wondering if there was a change.
Good luck, they sure are fun to shoot!

 

[USMCDOC]

Ahh yes, I misread it. Thought your reamer was spec'd at .2495
Just curious,did you spec it at .2515? Mine is a little larger and was wondering if there was a change.
Good luck, they sure are fun to shoot!

No.. that is just the way that Dave Kiff ended up cutting it..

 

[Frankr]

yea I would load the 24.0 and do some shooting.

 

[500Stroker]

24.5 in cold weather
24.0 in hot weather
Or 24.0 year round you might get a little more throat life.
Good luck

 

[edw]

High 23s-24. Maybe do another test at a further distance with .2 change

 

[USMCDOC]

24.5 in cold weather
24.0 in hot weather
Or 24.0 year round you might get a little more throat life.
Good luck

Well .. i did another test at 300 yards today.. fired first the 24.0 & 24.1 loads.. oh wow.. was it bad!
Then i shot the 24.4 & 24.5 loads.. well it started to tighten up with the 24.5. but still had some verticle in the group.. so i will try 24.6 through 25.0 tomorrow..

 

[USMCDOC]

Since it is going to be about 80 tomorrow here.. i think that i will also do a ladder test with the 2000MR..

 

[500Stroker]

Well .. i did another test at 300 yards today.. fired first the 24.0 & 24.1 loads.. oh wow.. was it bad!
Then i shot the 24.4 & 24.5 loads.. well it started to tighten up with the 24.5. but still had some verticle in the group.. so i will try 24.6 through 25.0 tomorrow..

Something changed if you did not get the same results. Testing is only good if it repeats.
Cold barrel vs hot? Was the barrel cleaned? Outside temp? etc. etc.

 

[jsthntn247]

Shoot over a chrony and get in the 2825-2850 range

 

[USMCDOC]

Something changed if you did not get the same results. Testing is only good if it repeats.
Cold barrel vs hot? Was the barrel cleaned? Outside temp? etc. etc.

Yes, something did change.. (temp) it was a tad warmer and it will be even warmer today! bbl was not cleaned.. nor will it be today either till this next test is done.

I did have a thought this morning though, when i was trying the Winchester brass (to which i ended up sending it all back to Winchester), it appeared that the working seating depth was 10K off the lands. Right now i am at 5K off, do you think that with the Lapua brass, that i should go back to that seating depth or stick with where i am at right now?

 

[alb]

With that data I'd probably go with 24.0 exactly just to keep it simple; looks like it's right around there.