Thread: 250 Savage Ackley Improved

Anyone here using/loading for one of these. Just starting off with this cal and could do with some info with modern powders to save a lot of trials and tests, most of the online data I can find is years old. Its a 24" 1 in 8 twist on a Sako L579 action planning on using 80 to 117gr bullets. any actually tried data would be appreciated so I can adjust down for a starting point.

https://www.nosler.com/250-3000-savage
Start with close to the max charge of varget (Adi 2208) for your given bullet weight and that should help you fireform your brass nicely.
I was wondering if you could actually use 6.5 creedmoor brass to form into 250 ai, as the two are not far from each other’s in dimensions.

Originally Posted by aimless

Anyone here using/loading for one of these. Just starting off with this cal and could do with some info with modern powders to save a lot of trials and tests, most of the online data I can find is years old. Its a 24" 1 in 8 twist on a Sako L579 action planning on using 80 to 117gr bullets. any actually tried data would be appreciated so I can adjust down for a starting point.

Greetings @aimless,
Nice handle by the way. Any data you find is likely to be from the intrepid years or from an enthusiast who loads right up to the pressure limits and beyond so this could be an interesting journey for you. First step should be to see how much you have gained by measuring the net case capacity. This is the remaining case capacity with the projectile. The length of the throat in your rifle will have an effect on this. You can do this with water (messy) or a ball powder. From there someone with a loading app should be able to generate some data for you. You will gain as much and likely more from increasing the pressure from 45,000 CUP to 50,000 CUP as you will from the improved case. Using a chronograph while you are doing you load development will be absolutely essential.
When Newton designed the .250 Savage he had in mind a 100 grain projectile at around 2,800 fps. For marketing purposes Savage wanted 3,000 fps and reduced the projectile weight to 87 grains. You should be able to have the best of both of these.
Regards Grandpamac.

The case capacity of a 250AI and a 25-08 (a.k.a. 25 Souper) are very close. I used 250AI data to develop starting loads for the 25-08, although as you point out there is not much current data in the net.
I assume that loads for 25 creedmoor would be similar, and more available on the net?

I can send you my loading data for 25-08 if that helps?

BB

After purchasing a Cooper Custom Classic in 250 Sav AI for my wife I reached out to Sierra Bullets for info on fire forming, Sierra use the 250 Sav AI for their daily quality control tests on their 257 cal projectiles.

One of Sierra's Techs Paul Box emailed me and suggested that i load a max load of IMR 4064 from the parent 250 Savage case data which is 35.3 grains behind a 100 grain projectile jammed into the rifling. This worked extremely well, the first four shots went into a 0.412" group at 100m and all the fire forming cartridges had very similar accuracy.

The Sixth Edition of the Sierra Manual has modern load data but Reloader 15 figures highly when it comes to Sierra's suggested accuracy and hunting loads.

We settled on 40 grains of RE 15 (41 grains is MAX) behind 100 grain GK projectiles using Winchester cases and Federal 210M primers. Out of the 22" 1:10" twist Cooper barrel these are producing 3088 fps with no pressure signs.

Greetings,
Layne Simpson did an article on the 250 Savage Improved in the October 2018 Handloader. His version had a 30 degree shoulder but results would be close to the AI. I found the article on the open internet so you should be able to find the article by searching. He used 42 grains of AR2209 with the 100 grain Sierra Pro Hunter for 3,068 fps. As always start low and chronograph to validate the data before working up. Each grain of powder should yield around 50 fps, You could also look for data for the .25 Creedmoor which is close to the same capacity but as an in wildcat pressures are liable to be super hot. Lastly I believe that Sierra may have data in their latest manual.
Regards Grandpamac.

Much appreciated guys, thank you. Yes BB, be keen to see your data, can never have too much info. Thanks Tech, I'll use that recipe for fire forming, I have Rel 15 so well on track.

With that twist have you thought of running the heavier hammer 98 grain bullets? Should be really good with a full case of 2209 or reloder.

Yeah thanks Nor-west, I'd try them but don't think they're available here and they cost an arm or a leg don't they? What do you pay for them in Perth, my daughters over there, maybe she could get some for me and send them out?