260 ackley calculation help needed

[codyadams]

great groups those kriger barrels really shoot well what reamer did you use for the chamber ????

I don't recall exactly, I'll ask my smith. I know that right after break in the OAL to the lands of the 140 Berger VLD was 2.870", and also that it is throated for VLD type bullets. I got my 140 VLD'S up to 3020 fps, but groups opened up to .75 MOA, which I consider unacceptable in my rifle. .5" groups @100 yards is pushing the limits for what I will accept during load developement. With my current VLD load, it will print in the .3" 3 or 5 shot groups or less every single time. My 10 shot groups with them fall under .5" every time if I do my job.

May I suggest trying the CCI BR-2 primers with your load...it cut a couple tenths off my groups and brought my E.S. from 20ish fps down to single digits, and I didn't change my powder charge.

 

[codyadams]

UPDATE

Finally I have this sorted out. I have made a few changes. Now using lapua brass and 130 berger vld #26503. Also now the zero range is 200

load 47g of H4831 in a 7-08 lapua case formed to 6.5 improved. cci primer. 130 grain berger vld touching the lands. rifle is a savage axis with a McGowen barrel

today it was 40f and light rain wind was 7 to 11 mph

range......elevation (MOA).....wind (MOA)
200...........0............................0
300...........3..........................0.3
400...........5..........................0.8
500..........6.5........................2.2
600..........10.........................3.5
700..........13.5.......................4
800..........16.8......................4.5
900...........20..........................5
1000.........24........................5.5


This load is super accurate. I am able to get sub MOA groups with ease.
I used this load last month and worked out the elevations and today was able to get first round hits at all ranges (except 800) using last months elevation data. At 800 I got caught by the wind, I had too much wind on.

Did you try any heavier powder charges with H-4831SC? I'm using lapua 260 Brass formed, CCI BR-2 primers, and 47.8 grains of H-4831sc seated to 2.875" OAL with a 140 grain bullet and didn't reach max until 49 grains....With this load of 47.8 I'm on my 5th reloading, I have not yet needed to trim brass, not needed to bump the shoulder back, and my primer pockets are still just as tight as they were when new. Unless that's where your load shoots the best, you should be able to work up to much higher velocity (and charge) safely and still be easy on brass with a 130 grain VLD.

 

[10X]

Did you try any heavier powder charges with H-4831SC? I'm using lapua 260 Brass formed, CCI BR-2 primers, and 47.8 grains of H-4831sc seated to 2.875" OAL with a 140 grain bullet and didn't reach max until 49 grains....With this load of 47.8 I'm on my 5th reloading, I have not yet needed to trim brass, not needed to bump the shoulder back, and my primer pockets are still just as tight as they were when new. Unless that's where your load shoots the best, you should be able to work up to much higher velocity (and charge) safely and still be easy on brass with a 130 grain VLD.

Have not done any load development with this weight bullet. I was at 47g with the 140 on the nosler cases and just stuck the 130 on the same load on a lapua case as a starting point and just like that it shot smaller groups at the longer ranges. I am thinking that its good as it is so why play with it. I am shooting steel plates and at 600 and 700 I can see the hits on the plate. I can aim at the mark made by the first hit (center) and hit that mark so I dont think changing anything can improve that. for these loads the ES is 9 with a MV of 3020

 

[codyadams]

Have not done any load development with this weight bullet. I was at 47g with the 140 on the nosler cases and just stuck the 130 on the same load on a lapua case as a starting point and just like that it shot smaller groups at the longer ranges. I am thinking that its good as it is so why play with it. I am shooting steel plates and at 600 and 700 I can see the hits on the plate. I can aim at the mark made by the first hit (center) and hit that mark so I dont think changing anything can improve that. for these loads the ES is 9 with a MV of 3020

With more velocity you could cut your wind drift down significantly, for instance...your 1000 yard wind dope @10 mph is 5.5 MOA, my load with the 147 ELD-M is 4.4 MOA...but if wind drift isn't a big deal where your at, and you don't need the extra energy, than sounds like you have a killer load ;-)