6.5 saum ladder test, with pics

[Alex Wheeler]

Load 61 and start working seating depth. Load a bunch at .020 in the lands. Bring them to the range with a seating die. Shoot 3 shots and push them in .005 at a time until you find the spot they like best. Then go back to the powder ladder with that seating depth and shoot a fine ladder from 60.5-62 in .3 increments. If its still a little sloppy, go to a smaller neck bushing. A proper throat for .140 vlds is .180" long. But when you must use a repeater there are compromises.

 

[Elk Hunter 338]

then it should be ready to rock... the hornady brass holds this round back a bunch.. find and build some 300 or 7saum Bertram norma or rem and it will come alive!!

If it was me and you want to run the hornady I would stick with the lower node and play with seating depth a little bit

 

[odoylerules]

Load 61 and start working seating depth. Load a bunch at .020 in the lands

You mean .020" off the lands not in right?

 

[Schnyd112]

Start long, jammmed, and work back, away from the lands. Some rifles/bullets like a little jam, Some like a little jump. A jam can help build pressure when the case is full and you aren't getting the speeds you want. Sometimes it it too much. Only way to know is check the whole range.

I also agree with more shots per group. You need more data to see the full picture. There may be something else happening that you aren't seeing in 3 shot groups. If something funny does happen, it makes it easy to move away from that combination.

 

[Alex Wheeler]

You mean .020" off the lands not in right?

Nope, .020 in and seat them deeper in the case as you go. Pressure change is minimal.

 

[Litehiker]

That is not a ladder test by any stretch.

Eric B.

 

[odoylerules]

That is not a ladder test by any stretch.

Eric B.

Can you elaborate on what you mean? I tried to duplicate Alex Wheelers ladder test method

 

[Elk Hunter 338]

That is not a ladder test by any stretch.

Eric B.

I want to hear this also!!

 

[Litehiker]

A "Ladder Test" consists of:
1. drawing a sighting ladder of perfectly horizontal lines 4 3/4" apart (for mil radian reticles), one above the other, for ten spaces on a vertical line running the length of the cardboard. (This requires at least a 4' tall piece of cardboard.)
2. Attaching the ladder board to a solidly mounted target frame PERFECTLY VERTICALLY (use a level)
3. Shoot three shots at the lowest horizontal line, adjust up one mil on your turret, shoot the next 3 shots, and go this way on up to the top (10th) line.

Your rifle MUST use a scope level and it must be level for each shot.
IF your scope tracks perfectly vertically and IF your reticle is not canted in your scope (at the factory) then you should have holes very close to the vertical line at each cross line. If not , i.e. if they gradually "lean" left or right, then you have a canted reticle or vertical turret problem. A canted reticle, if very slightly canted, may not be visible to your eye but this test will detect it.

Eric B.

 

[Rick Richard]

Ladder Test definition.

With a ladder test, you take your starting load and load one round each with a slightly increasing amount of powder until you reach your max load for that cartridge. You then fire each round using the same aiming point to see where the bullets start to form a group.

 

[Elk Hunter 338]

A "Ladder Test" consists of:
1. drawing a sighting ladder of perfectly horizontal lines 4 3/4" apart (for mil radian reticles), one above the other, for ten spaces on a vertical line running the length of the cardboard. (This requires at least a 4' tall piece of cardboard.)
2. Attaching the ladder board to a solidly mounted target frame PERFECTLY VERTICALLY (use a level)
3. Shoot three shots at the lowest horizontal line, adjust up one mil on your turret, shoot the next 3 shots, and go this way on up to the top (10th) line.

Your rifle MUST use a scope level and it must be level for each shot.
IF your scope tracks perfectly vertically and IF your reticle is not canted in your scope (at the factory) then you should have holes very close to the vertical line at each cross line. If not , i.e. if they gradually "lean" left or right, then you have a canted reticle or vertical turret problem. A canted reticle, if very slightly canted, may not be visible to your eye but this test will detect it.

Eric B.

yes in fact this is a ladder to test to test several things >>>> tracking and level of your optic!!!! this however in short is not the "ladder test" in which we are discussing were as in each powder charge increase the impact in fact act like a "ladder" climbing on target and forming nodes as they climb, then as Alex described fine tuning with seating and powder charge changes making your load optimum for said bullet powder combo!

 

[Litehiker]

yes in fact this is a ladder to test to test several things >>>> tracking and level of your optic!!!! this however in short is not the "ladder test" in which we are discussing were as in each powder charge increase the impact in fact act like a "ladder" climbing on target and forming nodes as they climb, then as Alex described fine tuning with seating and powder charge changes making your load optimum for said bullet powder combo!

_____________________________________________________________________
OK, I see that you are making, in actuality, a velocity test. Same zero, faster velocities climbs the groups upward. So instead of shooting at different smaller targets on a large target you are keeping vertical zero and climbing each 5 shot group until you hit the best node. 5 shot groups give a better sample of group size than 3 shot groups.

You are talking load workup and I am talking a scope tracking test. In optics test circles the term ladder test refers to the one I described. This is the first time I have ever heard of a ladder test referencing load work-ups. To me it's an odd test but maybe a "poor man's" velocity v.s. grouping test.

BTW, Velocity is meaningless if the groups are 5 MOA. Yes, you get various nodes (group sizes) as you increase velocity and I guess you save target paper with a velocity ladder test but using a good chronometer like Lab Radar will give you a record of actual velocities. A Magnetospeed V3 is a less expensive alternative with the same record keeping ability including ES and velocity averaging.

Eric B.

 

[375fan]

To the OP, after looking at your pics, might I suggest 60.9 at .010 off the lands.
Thats actually my load for my one saum using 140 hybrid.
Have a second saum with same contour as yours, using 60.9 with 143 ELD-X.

 

[Litehiker]

"MOST EXCELLENT" BRASS
Alpha makes the best American made rifle cartridge brass. It is considered to be at least as good as Lapua brass in terms brass quality and manufacture quality.
$99./100 or $495/500 rounds (or so it appears to be on their site)

Eric B.