Ladder test 260 Berger hybrids

[boonewsm]

Berger Hybrid 140 ladder test with H4350
Lapua 260 brass on 3rd firing
WLR primers
Each load weighed on gem pro 250

Dta Srs A1 factory 26 inch barrel with 8.5 twist.
2.930 OAL
Seems my lands are almost out of reach on this barrel. Not sure what happened but they measure 2.050 to lands in this barrel. These are jumping .020.
These are 3 shot groups measured out side to out side.
Shot over a magneto v2

DA of -1600 today with snow on the ground.


42.1 grains. Average 2790
Sd 6
Es 15
Group 1.07

42.3. Average 2805
Sd 18
Es 35
Group .9

42.5 average 2811
Es 2
Sd 1
Group .61

42.7. Average. 2817
Es 17
Sd 9
Group .55

42.9. Average. 2829
Es 16
Sd 9
Group .69

43.1. Average 2840
Es 24
Sd 12
Group 1.22

43.3. Average 2855
Es 5
Sd 2
Group .628

43.5. Average 2869
Es 48
Sd 27
Group 1.04

43.7. Average 2878
Es 14
Sd 7
Group .672.

I'm thinking I should try some more at 42.7. Looks like a good node. Maybe need to try the 43.5 and make sure nothing went wrong loading them. That was the node with the 140 berger vlds.
What do yall think?

 

[AIdog]

I would look more in to 42.5 very low es and sd with exEptional accuracy...

 

[Thor2j]

This isn't really a ladder test per say. With a ladder you are looking for vertical deviation with different powder loads. You are trying to find a spot where changes in powder will result in a minimal poi shift. That being said, I would agree with 42.5 but as much for the fact that .2 up and .2 down have the least effect on velocity change of the bunch.

Also not sure about your measurements to the lands. I have a dta barrel also and mine is 2.2770 to the lands with the hybrids. Yours seems off a lot .

 

[redbullitt]

+1 on shooting an actual ladder if possible. The numbers are all very useful, but they are even better when you have the ladder to back it up. You are seeing how well the load is working, but you are not really seeing how it is timed with the barrel vibrations. Add what you have right there to a nice ladder at 4 or 5 hundred yards. THEN you will have all the info you need.

Take a target out far. Load up 1 round, say .3 or .5 grains apart depending on distance. Get zeroed in on a nice spot on the target. Shoot round number 1 and mark it. Shoot the next and mark it etc. You should wind up with a nice vertical string with a few shots landing on the same horizontal plane. THAT is a good spot for your barrel. Do your OCW test (like you did already) somewhere near those charges you find in the ladder. That is what usually works for me at least…

That way both tests will reinforce each other and you won't really be wondering if you missed a better node. It is also very nice to actually see how your load will do at distance. Sometimes short range testing seems to wind up with a load that does great up close, but not out far.

 

[wadebrown]

With only 3 shots I would not put much faith in the ES and the SD has no value with a sample size that small.

 

[boonewsm]

Actual ladder test done at 800 yards today. Started at 41.1 and worked up to 43.8. All the data from above still applies. Wind swapped on me for the first 3 then settled. Same POA used on all shots. No wind hold.

I've had this happen to me before on a ladder with a 223 at 400 yards having a lower powder charge shoot higher the a higher charge. Is that common? Could have been shooter error, being shot from an atlas and monopod off a bench but I didn't feel like I pulled any.


Which node do yall think I should work with? Having the info from the op to go with it.


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[boonewsm]

Looking at it with a little more time to think about it I think i will load up 3 or 5 at 42.6, 42.8, 43.0 and shoot them at 800 to see what kind of groups/ vertical spread I get. Looks like somewhere in there should be a good node and decent velocity.


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[drn1234]

boonewsm, I have the DTA in 260 so I thought I would post my results also to compare and share notes.

I have the older DTA and my measurement to the lands was 2.308.
I measured this thing about ten times and kept coming up with the same approximate measurement.

Took a litte off for my reload OAL and then found out that the round would not fit in the mag. I had to drop my OAL to 2.260 just so they fit.

I am running H4831 and my ladder at 500 yds grouped around 45.8 to 46.2 with some very close to 46.8

My 100 yard loads are as follows
5 shots over magneto
Hybrid 140, lapua brass winchester primers

45.6
2754
SD 10
ES27
.65

45.8
2772
SD 10
ES 26
.5

46.0
2776
SD 9
ES 23
1.1

46.2
2795
SD 12
ES 33
1.0 minus one shot, seems like one may be shooter error not sure.

46.4
2799
SD 11
ES 31
.9 again with one flyer

46.8
2819
SD 6
ES 16
1.4 and really opening up

Looking like 45.6 to 45.8 is the best and should start working on OAL and see what happens
what do you think?

 

[boonewsm]

Well I ended up loading 5 at .2 grain increments from 42.4 to 43.2 and shot them at 400 yards yesterday due to the wind. I don't have all the data with me at the moment but the 42.8 had .8 inches of vertical dispersion at 400. The wind was gusting 10 to 25 mph buy still was with within 3 inches of horizontal. 42.6 and 43 were close but 42.8 was the best.


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