300RUM 230 Berger ladder test

[gaps]

Here is my first ladder test I've ever done. I'm looking for input and if I'm on the right track. Here is the info.

Phoenix Custom Rifles 300 RUM
Blueprinted/Trued 700
PTG firing pin/spring
H-S Precision Sendero takeoff stock
Pillar bedded
28" Kreiger Barrel
Badger Thruster Brake
PTG .25 lug
Timney 510 Triger @2lbs.
Nightforce 40moa rail
Vortex Razor HD 5-20x50 EBR-2B 25moa turret
Vortex Rings

I loaded the 300 Rum with brand new remington brass, fed 215m primers, 230 berger match hybrid target, brass oal @ 2.40, coal 3.918, and retumbo.

Shot @ 300 yards prone with rest and rear bag. Zero wind, 50 degrees, 2100ft elevation. Dialed 2 moa up from my 200 yard zero with an estimated muzzle velo of 2900. Shot two sighter shots and then proceeded.

1.) 84.0
2.) 84.5
3.) 85.0-bad primer didn't ignite
4.) 85.5
5.) 86.0
6.) 86.5
7.) 87.0
8.) 87.5
9.) 88.0 MAX
10.) 88.5 MAX+
11.) 89.0 MAX+
12.) 89.5 MAX+

From looking at the pic I believe shots 7, 8, 9 are the node. They Measured .869 ctc at 300 yards.

What do you guys see? I am I reading this correctly? I may go back and load shots 7,8,9,10, 11, 12, and maybe 13,14,15 just to see if I can see my max pressure. What do you think? Also I want to move my coal to 3.900 so I am not in the lands. After the primer failed on shot 3 I lifted my bolt and pulled back but only the case and powder came! Bullet was stuck and powder everywhere. Luckily I always have my range box with me and quickly cleaned up the mess! This is getting fun if I am able to improve the 7,89, group! I also have 3 pounds of H-1000 and 8lbs. of Retumbo. Im thinking of doing a new ladder test with H-1000, would this be a waste of time and money? Please let me know if I'm on the right track, Thanks!

 

[upacreek]

Forgive my lack of knowledge, but is this a normal procedure? I have always done this except 3 rounds per load. I would look for groups, or flyers. Back then seating depth adjustments weren't even a thought. I would hunt for groups solely based on powder charge.

Sorry to hijack the thread. Just never heard of this. Had to ask.

 

[Broz]

I would load up some more rounds of #8 and shoot a few 3 shot groups at 300. Right where I would expect the node to be, a few grains below max.

Jeff

 

[oldno7]

I would load up some more rounds of #8 and shoot a few 3 shot groups at 300. Right where I would expect the node to be, a few grains below max.

Jeff

Jeff
7,8,9 seems to have more vertical spread than 10,11/5,6.

Why not develop around those areas?

I've only done a couple ladder tests and I appreciate your knowledge in this area.

 

[Broz]

Jeff
7,8,9 seems to have more vertical spread than 10,11/5,6.

Why not develop around those areas?

I've only done a couple ladder tests and I appreciate your knowledge in this area.

7,8,9 are under an inch at 300 yards. That's .3 moa at 300 yards. I feel the other errors both human and mechanical could easily be larger than the .3 moa of vertical. I picked #8 because it was right in the center of the node. If we are correct that should transfer to a wider node in many ambient temps and the indication at this point is under 3" of vertical at 1000 yards. But, all this needs to be confirmed with more 3 shot groups and barrel cool time.

Jeff

 

[gilmillan1]

Don't waste any more time shooting ladder tests. You already know where the node is. Now you can start playing with your seating depth But I think that you will get a pretty nice group with powder charge 8 and your current seating depth. You are very close to being done testing your load.

 

[oldno7]

gaps

Where either of your fouling/sighter shots using 88.5-90gr.?

Were they both loaded the same?

 

[CB11WYO]

Question, as I haven't ever done this with only one round per powder charge.

How many shots do you shoot in a string before letting barrel cool? or do you let it cool between each shot?

Maybe OP, Broz or somebody could fill me in...

Thanks

 

[gaps]

gaps

Where either of your fouling/sighter shots using 88.5-90gr.?

Were they both loaded the same?

The fouling shots were 84gr and 88 but both were "blems" since they were seated out to 3.924 instead of the rest at 3.918. Since I don't have a bullet puller yet I decided to use them as sighters.

 

[gaps]

Thanks for the input. I will load some more around shot number 8 and see how they do. I also may do a ladder with H-1000 too just so I know how my rifle likes it...

 

[Broz]

Thanks for the input. I will load some more around shot number 8 and see how they do. I also may do a ladder with H-1000 too just so I know how my rifle likes it...

Good plan!

Jeff

 

[oldno7]

The fouling shots were 84gr and 88 but both were "blems" since they were seated out to 3.924 instead of the rest at 3.918. Since I don't have a bullet puller yet I decided to use them as sighters.

The 88gr(fouling). was the one 1/2" to the right of 11?

 

[gaps]

The 88gr(fouling). was the one 1/2" to the right of 11?

To be completely honest I'm not sure...I have some video of each shot I can look at but I'm not sure if we videos the sighters...

 

[tom m.]

Never ever no got a 215 to not ignite, double check everything mechanical first. Then move on with 8ish. Were you seeing pressure, or just listing max as per the data book? Once you hit pressure you can almost bet it will shoot at 2-3% under.

Tom