I just obtained a 450 Ackley and am looking for other's experience with this round. I am excited with the project of reloading this cartridge and can't wait to start. So far I have not had any time to do anything with it. Next week I am going to cast the chamber and my dies and hopefully start on some loads for it.
Does anyone have some good personal loads worked up? For now I am just going to work with 350gr and 500gr bullets but want to work with 450gr bullets at some point.
A couple of questions I have come up with:
-My barrel is marked ".450 Ackley Improved" yet I always thought that .450 Ackley Magnum was the nomenclature for this cartridge and was not aware of an improved version. This leads into my next question.
-I have both A-Square marked brass and reformed 45 basic brass. The A^2 brass looks unfired and has a fairly long, rounded shoulder while the reformed basic brass a very sharp stepped shoulder, much more square. I know this is a wildcat cartridge and therefore not standardized but what is the more accepted shape? I am going to cast my chamber and my dies next week to see what their exact dimensions are.
-Have others noticed A^2 brass having smaller than normal primer holes? Mine appear (have not measured yet) to have holes smaller that my decapping pin or very close.
the brass used to be fireformed with .375 brass necked up, then sized down. the "sharp shoulder" is consistant with all acley imp cases and, depending on caliber usually amounts to a 5-15% increase.
Originally Posted by j_h_nimrod
this cartridge (suitable for elephants), headspaces on the belt so the shoulder is for bullet retention.
recoil is ponderous (?) with full power loads, but can be loaded back to .458 velocities. of course this tremendous power is the sole reason for the cartridge.
try 90 gr of 3031 with the 500 gr bullet. with a 24" barrel it should crono about 2500fps.
**as always, start a bit lower and work up. be consistant with primers and cases as this can be hot.
Used to own one of these buggers but it was brutal on my shoulder and sold it. Not sure of the loads I used and chrono'ed but you will not see 2,500 fps with a 500 grain bullet. More like 2,300 if your lucky.
It is a good round but in this day and age offers no real advantages over the 458 Lott with it's inexpensive brass and reloading dies.
If I did not have 45 basic brass necking up H&H brass works but now a days I would start with either .416 or 458 Lott brass as it would result in thicker necks. Have not tried it but would bet running a Lott case through your resizing die would give you a case that you could load. Cases might be a little short but wouldnt be a big deal.
Never used A square brass so I can not comment on your questions on that.
I know that the Ackleys are characterized by their sharp, 40 degree shoulder but in my searches and looking at different pictures of this cartridge, and the 2 different cartridge variations in my brass, I have seen two distinct variations. One with the sharp shoulder and the other with more of a rounded neck. I guess it really does not matter, as long as my chamber matches my dies.
I have a bit of 458 Lott that I could use to make more but I will probably end up buying the correct headstamped brass and sizing.
I have a feeling the recoil is going to be brutal, but I have a good recoil pad and a 16oz mercury recoil tamer when I get the chance to install it. I think I am going to try and get this rifle up to about 10.5 pounds and that should make it manageable.
I've never had a 450 ackley, but I have had two 458 lotts.
I would assume the A2 brass simply needs to be fireformed. I've never seen any reference to a rounded shoulder in any ackley chamber. I'm not that familiar with the history of the round, but since it doesn't improve an existing chambering I'd think that 450 Ackley Magnum would be a more accurate description then ackley improved.
There is quite a bit of 458 lott data out there, I'd use that as a starting point and work up.
To the poster that claims the 450 ackley will push 500's 2500 fps from a 24" barrel, I would be highly sceptical of such claims, and would give a strong warning to anyone attempting those velocities from the ackley. The 458 lott will do a tad over 2300 fps with 500's, and folks I know who've loaded the 450 ackley say they can push 500's 2350 fps, and redline is 2400 fps.
Have fun with the rifle, the big 45's are in a class of their own.
.450 Ackley Magnum
Yes you are right... the .458 cal. cartridge is .375 H&H-based and called the .450 Ackley Magnum. The "improved" mark is a gunsmith's mistaken stamping for other Ackley improved cartridges/chambers with 40 degree shoulder angles and so on.
Originally Posted by j_h_nimrod
I run a .458 Lott, however other than - .050 in OAL... there is no in the field practical difference... Easiest way in my opinion is to go out and get a box of .375 H&H or .458 Lott and fire-form to your gun's chamber. In your .450 Ackley Magnum you can shoot .458 WIN MAG and .458 Lott. I'd go the Lott and you'll likely get easier, more uniform, less time dinking around results. Sight in --- You may find both give good accuracy and velocity... making for a great reloading recipe.
Curious what kind/make action does your rife have? What kind of stock? What barrel length?
Another poster wisely advised not stretching to 2500fps... this is sound advice!
My 16.5" Lott averages 2285 with factory Hornady bonded 500 Grainers. You'll feel this in your back teeth the next day wondering what you were chewing on... but controllable/manageable and tolerable doing your part downrange. MY Lott is very-very accurate!
From what I have found, the more I research, is that there appears to be 2 distinct variations on the .450 Ackley Mag. After careful examination of my rifle chamber and the chamber of my dies it would appear that I have a rifle of one variation and dies of another. I will still be able to use the dies but will not be able to full length size. To see what I am talking about pull up:
http://www.accuratereloading.com/450ackleymag.html this shows a good picture of what my fireformed brass and chamber looks like
http://www.midwayusa.com/viewproduct...tnumber=709516 this shows what my new brass looks like and what my dies fit
All-in-all it is a wildcat and I would expect to have to do some tinkering, no problem there.
My rifle is a stainless steel Montana Rifle Co. Model 1999 with 22.5" barrel. I am not sure if it was barreled by MRC or by another smith. The stock appears to be a laminated Boyds that has been customized with a bit of lead. The stock does not fit me well so I am working on a new one. I will probably have another couple inches taken off the barrel too, I will carry it a bit first and see how it handles.
I also have a 375 h&h and a 458 Lott with a good stock of brass. I will probably just work with the A^2 brass, keeping correct headstamps. I may stick a few Lotts in there though if I run into problems. I could never be a good wildcatter, I can't stand incorrect headstamps.
I definitely will not try for 2500 out of this, I think 2300-2350 with a 500gr bullet will be plently. I like being a bit conservative. I am looking forward to some 350 grainers at ~2900 fps though, ought to be a good deer load
I have had a chance to work with the rifle a bit now and really like it. I ended up getting weight to 10.75lbs and it is not too bad to shoot at all; only mildly teeth rattling. So far I have had good accuracy results but need to wring it out some more.
Note on A-Square .450 Ackley Magnum brass: While very pretty there have been 2 major issues with this stuff. The first, as I suspected, the flash hole is too small for the decapping pin and I have had to open all of them up. I should have taken an initial measurement but I did not. All I can think is they use a .0625 small rifle flash hole instead of a large rifle .082. The other problem is that the primer pockets appear to be almost military crimped and seating primers required cleaning the pocket up. For brass that costs $2+each you would think they would have done a better job. I have been happy with other A^2 products; this is the first flop.