Developing loads for Ackley Improved cartridges

[RW]

I would like to know the best way to develop loads for the Ackley Improved cartridges? Would powders that work for the standard version work most of the time, working up, watching for pressure signs and velocity with chronograph. With the shortage of powder and other components I would like to use some of the powders that I have on hand such as Norma MRP, vihtavuori and others that can be found available. Some of these powders are not listed for the standard version so there is not a starting point such as the 6.5x06 and 6.5x55 and so on. So what would be the best way to go about getting a starting load with powders that have a similar burn rate? I don't have Quick Load and looked at the demo for it and it looks kind of complicated and a lot of technical things that are kind of intimidating and not relevant to what I need! Maybe if I had it and worked with I would understand it more! With components being in short supply I hate to do a lot of unnecessary experimenting with components that are hard to come by! Love to hear your input, as always, I have learned so much at this site, I can't Thank You enough, Ron

 

[JRS]

What weight bullets will you be using in the 6.5x55?
I have plenty of data for the old girl using MRP

 

[savagedasher]

6.5 +55 would be my choice RL 22 N560 The best 2 powders is MRP and H4831. The 6.5 +55 will do everything that a 6.5 +06 will do with less powder. Larry

 

[RW]

I have some 140 Bergers and some 129 SST And I plan on trying some 130 Bergers in both my 6.5 ackleys I have both 6.5x55 ai and 6.5x06 ai and real excited about the improved sweede as it was the first centerfire rifle I shot 50 some odd years ago!

 

[JRS]

Sent you a PM regarding load data.
Don't get over zealous with the charges :-X

 

[Catfish]

Don`t expect to see a great increase in velocity. The rule of thumb is you will get an increase in velocity that is 1/2 the percentage of the increase in case volume, at the same chamber pressure.

 

[AckleymanII]

Start at the max load for the parent case for that bullet and work up. Sweede data can be on the light side due to all the old rifles out there. I always run higher chamber pressures on AI cases because the case grips the wall so well with the AI design, and this is where there is usually the best accuracy node also.

 

[rardoin]

In the 6.5 x55 BJAI I am pushing a Nosler RDF 140gr, 0.010" off the lands at 2930 fps (+/- 10 or so) using 50.8gr H4831sc / Wolf LR primer in Lapua cases fired about 5 times. IIRC water capacity of my cases are just under 63gr but I lost that data on my phone notes and don't have access to my book at the moment. I have not tested that load at 600yds yet but at 300yds in near zero wind I am getting groups at 0.010" in and 0.010" off the lands at under 0.28 MOA...the loads out of the lands had less than .2" vertical so that is the depth I will shoot. I am about to test RL23 for max pressure/velocity this week just for the heck of it and I can post results when I get them. I really like this cartridge.

 

[spaniel]

Typically I have found powders that worked in the non-AI version to work in the AI, with the same bullet. But the BEST powder may differ.

I'll use a near-max load for the parent to fireform, and then as the starting point for a true AI load development. The amount of velocity increase to expect really depends on the AI being considered.

 

[Brians356]

Don`t expect to see a great increase in velocity. The rule of thumb is you will get an increase in velocity that is 1/2 the percentage of the increase in case volume, at the same chamber pressure.

In the latest American Rifleman, John Barsness wrote that the rule of thumb is 1/4 the percent increase in powder volume. I wrote the magazine, saying 1/2 the percentage (or more) is commonly achieved for parent cartridges which are not already overbore to begin with, such as 250 Savage, 30-30, and 6.5x55 Swede.
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