Load data for a 270 Ackley Magnum, cast and jacketed. Whatcha ya got?

[15meter]

Hi,

Buddy inherited an original P.O Ackley smithed 270 Ackley Magnum. Complete with his dad's correspondence with Ackley himself. Very cool old rifle.

He asked me about reduced loads for it. He's got the original Ackley #1 manual with that data.

I went on Load Data and found some loads, not quite what he's looking for.

He's looking for any additional load data he can come up with, especially load data that isn't quite as vigorous as Ackley's original data.

We know about the Trailboss option, I called and asked Hodgdon about using the H4895 60% rule for reduced loads with the IMR-4895 data I have and received a firm NO to that notion.

They have no tested data for this cartridge either, nor any suggestions.


HELP!

[Mk42gunner]

I never had one, but I think it compares pretty closely to the .270 Weatherby Magnum. Might give you some ideas, I wouldn't blindly take data for the Wby and use it without doing more checking.

Robert

[Texas by God]

Is it based on the full length H&H case or is it 06 length? I used to have the old Ackley book but I passed it on……
It could be close to a 7mm STW- or a .270 Weatherby depending on capacity.


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[Kestrel4k]

I just opened up Quickload and it does have a 270 Ackley Magnum cartridge choice (case length 2.460" BTW).
QL is so useful to me that I cannot handload without it; this specific situation would be another good reason to get it.

Its entry for 270AM cites a water capacity of 74 grains.
270Win, 67
270WSM, 79.5
270Weatherby, 82

[15meter]

It started out on the original H&H belted case because that basically was the only big capacity, STRONG, semi-common case that was available without going to the rimmed Nitro Express cases. And I don't think the N.E. cases are anywhere near as strong. Plus the whole rimmed in a bolt action slant back magazine thing to deal with.

I believe it can be formed nowadays from 7mm Remington Mag cases relatively easily. It was developed after Winchester brought out the Model 70 in 375 H&H, making those case much more readily available to the wildcatters.

Since I've posted, I found a reference on the web to data for this thing in Speer's #4 manual. I don't have a #4, but I do have a #5 and the data was still there. It had fallen out by Speer #7. I suspect that there were not a lot of these made. Just lucky I found what I did.

Having never gone that far afield on extrapolating data, with 270 Winchester having less case capacity, going into a larger case usually drops pressure, and case shape being semi-similar, AKA bottlenecked, is trying reduced load 270 Winchester a viable solution?

I've got bunches of SR4759, I would think I could find more than a few 270 Winchester loads out there.

Or do I have another Chernobyl on my hands?

[Kestrel4k]

Here is info & reloading data from the P.O. Ackley Handbook Vol.1;
https://www.dropbox.com/s/2coraq0nxalvkoc/20230418_210837.jpg?dl=0
https://www.dropbox.com/s/0429gvd4h4v6qyi/20230418_210918.jpg?dl=0
https://www.dropbox.com/s/jioa4kssvhklklf/20230418_210948.jpg?dl=0

[Teddy (punchie)]

What is he trying to do?

Reduce recoil?

Use less powder?

There is only so much you can reduce the volume without getting into the... double ignition theory. Less is not always more.

[Rapier]

Sounds like you want to reduce the recoil. If so, you might try the old reduce the Ackley published load by the powder lot chane, nominal 10%, and then the bullet weight. At the time Ackley was writing, the 270 bullet choices were not what they are today, the 6.8 cartridges has brought about more light weight bellets.

[15meter]

Reduced recoil is the goal, I don't anticipate him hunting with it, he's a Michigan deer hunter, this or the 350 Ackley Magnum that he inherited are good enough to drop a deer through the 12" oak tree it's standing behind. He just wants to be able to shoot it semi-comfortable. He's had multiple back and heart surgeries, massive recoil is not high on his list of fun things to do.

He is extremely happy that he can shoot it. His older brother inherited it from Dad years ago, and not being a reloader he thought that the ammo that came with the rifles was all there ever was going to be. Mark inherited the rifle when his brother passed away. I walked Mark through forming his own cases for both rifles after he saw me on the range with a buddy I had formed brass for. 7x61 S&H, 280 Ross or some other rifle that requires unobtanium ammunition.

Keep the old weird ones out shooting. Too much fun not to.