450 Ackley on Win 70 action

ok.. just read this.. The .450 Ackley provides a worthwhile velocity increase over the .458 Winchester Magnum of approximately 200–400 fps, and 100–150 fps over the .458 Lott, depending upon whether factory loads or hand-loads are compared and what propellants are available for hand-loading.

an extra 150 feet per second actually means something when you are shooting 500gr at a time.

I shoot my 500 gr projectiles as soft cast at 1500-1600.. enough for me :)
 
The Ackley can use Lott brass and can fire 458WM or Lott ammo in a pinch so I don't really see any downfalls of going all the way to the Ackley, keep in mind none of these are needed and I have no safari's in the works, I just like to play.
 
It actually sounds kinda cool.

Many owners of .450 Ackley rifles have taken to using .458 Winchester Magnum ammunition when Ackley ammunition was unavailable or too expensive. Now that .458 Lott is factory loaded it can also be used. The fired Lott cases are simply fire-formed to the Ackley chamber. The .458 Winchester Magnum cases fired in the Ackley chamber form a small neck (about 1 mm long). This does not preclude re-loading these cases. Resizing in a .458 die brings the neck back to the correct dimensions.

Turns out I even have a couple sets of .458 dies and a couple boxes of hornady 500 gr round nose in case I ever get one in the future... :) This is normal behaviour right? I can't be the only one with reloading dies and supplied for guns they don't own.

This is interesting to me because I have a friend with a Ruger #1 .458 mag. I should talk him into it, it's easy for him. He likes silly things..
 
I have fired thousands of rounds from the Ackley, one thing I can tell you is they are hard on stocks. If your mod 70 doesn't have an exceptional piece of wood don't bother unless you're also in the market for a new stock.
And yes, my stocks were all properly bedded, with secondary recoil lugs on the barrel. They tend to split the grip and not from the tang, same problem I heard Ruger had with their 416 African.
With a 25" barrel I was getting 2550 fps with 500 gn Hornady softs and solids, if you do the math you will see this exceeds 7200 ft/lbs of energy. This also means recoil is 50% greater than the 458 in the same rifle and recoil velocity is also increased by 25% giving even more perceived recoil, she's a handfull!!
Will it fit? Should fit fine but you will need to modify the magazine. Win makes the 375 H+H in this same rifle and the COAL is the same.
The Ackley is famous for "bullet pull" that will jam your magazine up solid, I made all my brass by fireforming 375 H+H which gives thin necks and minimal bullet tension. Had nothing else back then. Crimping in the cannelure helped about 90% but still 4th or 5th in the magazine would usually pull and jam (602 Brno)
One thing for sure is you'll never buy a used one that is "shot out"!!!!!!!!!!!!

Best of luck, great cartridge if you can keep it in wood.
 
450 Ackley

I also forgot to mention that your optics and mounts will spend as much time on the ground as on the rifle. I ended up with a custom 1 piece steel base mounted with 6-#8 screws and 4 steel rings on a Leupold 1.5-5 Vari X III.
I like the Leupold but they were also the only company back then that would give me a new scope every 3 months. Most optics manufacturers, if you read the fine print limit their warranty to 375 H+H. I found out the hard way with Swarovski.....nothing larger than 338 Win mag.
I could go on for hours, regardless, I love the cartridge and am thinking about building another, as I just picked up another 602........ HHHMMMMMM.
They're so versatile, everything from gophers to T-Rex, without a hiccup.
 
I glass bedded a one piece Near Alpha Hunter on my M-70 Safari, it has a recoil lug which hooks behind the front bridge. The 1-4X Nightforce has an etched reticle and has proven to be an excellent scope for this sort of application.

My rifle is still chambered for the .458, but I am playing with the idea of a .460 G&A/.460 Ultra. I'm not a fan of straight wall rifle cartridges in bolt guns and the Ultramag cartridge wouldn't require any changes to the bolt face as would the .460 Weatherby or the .450 Rigby. The new Winchester Safari has very limited cartridge capacity, and I would probably opt for a stock change in any case so I could get a drop belly magazine. As it happens McMillan produces such a stock for the M-70, which is inletted for a Sunny Hill magazine and bottom metal. The McMIllan stock I put on my Brno 602 .375 Ultra I glass and pillar bedded and had cross bolts installed; using rebar in heavy recoil applications is a good thing.
 
c-fbmi said:
I have fired thousands of rounds from the Ackley, one thing I can tell you is they are hard on stocks. If your mod 70 doesn't have an exceptional piece of wood don't bother unless you're also in the market for a new stock.
And yes, my stocks were all properly bedded, with secondary recoil lugs on the barrel. They tend to split the grip and not from the tang, same problem I heard Ruger had with their 416 African.
With a 25" barrel I was getting 2550 fps with 500 gn Hornady softs and solids, if you do the math you will see this exceeds 7200 ft/lbs of energy. This also means recoil is 50% greater than the 458 in the same rifle and recoil velocity is also increased by 25% giving even more perceived recoil, she's a handfull!!
Will it fit? Should fit fine but you will need to modify the magazine. Win makes the 375 H+H in this same rifle and the COAL is the same.
The Ackley is famous for "bullet pull" that will jam your magazine up solid, I made all my brass by fireforming 375 H+H which gives thin necks and minimal bullet tension. Had nothing else back then. Crimping in the cannelure helped about 90% but still 4th or 5th in the magazine would usually pull and jam (602 Brno)
One thing for sure is you'll never buy a used one that is "shot out"!!!!!!!!!!!!

Best of luck, great cartridge if you can keep it in wood.
Click to expand...



i have a ruger #1 in 45-120 that has a similar problem , it is very hard on the stock , and pounds out the bedding compound easily .

lately i have been using 3m's panel bonding adhesive as a bedding compound and it seems to be holding up not too bad .
 
I found that 2550 was just pure excess - keep it around 2400 or even 2300 and life is better with the Ackley.


First shot at a ... say elephant - go for the 2500, but for the rest of life, 500 gr at 2350 will put a solid through most anything.
 
Full power loads for my application would never be needed, like I say it would only be for playing and the odd moose or bear, I have a Win 70 stainless in 375 H&H for hunting tasks also.

Would a good synthetic stock help with the stock spliting problem or is wood the way to go?

The other thing that worries me is that I can never hold on to anything for very long and the resale or at least chance of recouping my money would be best if the rifle was left original.
 
I detest synthetic on heavy rifles, a nice dense piece of walnut is the only way to go IMHO. If you're going to back off to 2300 fps go with the Lott.
A good buddy of mine had a 450 Ack built but put on a muzzle brake, and had none of the issues I had. Wbys in 378 and 460 all come with brakes and I'm told, but don't know for a fact, that Wby won't warranty stocks if brake is removed and rifle used without it.
But as someone's sig line says "brakes are for sissies" which is my motto as well.
 
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