Well I've been looking through a few of my load manuals and have seen a few of the Ackley cartridges listed. I'm curious to know what are the real gains of one of these rounds and what is all involved in loading and forming the cases? The one I am looking at is the 30-06 Ackley Improved. Thanks.
The Ackleys
- Thread starter sigarms226
- Start date
Usual gains are 50-100fps, depending on the cartridge in question. Forming consists of fireforming an unimproved case in the AI chamber to puff out the shoulder and body taper. Some people use a light load with a bullet, some form with a load that consists of a light pistol powder charge topped with cream of wheat or other filler. After forming, you would neck size and trim (if required), then you are good to go with regular loads.
Mark
Mark
That's right, and the 30-06 AI will gain at most 50 fps unless you crank up the pressure. Certainly not worth the expense of rechambering and of more expensive dies. Any possible saving on brass (they are supposed to stretch less) is dubious.
I have a number of Ackley chambered rifles, the 30-06 AI among them. As mentioned, you don't gain much (conversely, with some cartridges, you gain quite a bit, the 250 Savage for example). Basically, on any improved case, you figure out the increase in case capacity as a percentage, then divide by 4, and that will give you your increase in velocity. It's rough math, but it will get you close. As an aside, my 30-06 will push 180 gr bullets to 2900 fps with 4350 powder. FWIW - dan
Pathfinder
CGN Ultra frequent flyer
- Location
- Northeast Ontario
Also the chambers should be setup to fire the unimproved Case to fire form if needed which is why they have to be set back a bit to a crush fit in order to control headspace.
Ive given it some though....decided it wasnt' worthwhile rechambering a rifle. On a new barrel I would have to consider it.
Not likely to have much of an improvement, as the .308 case (parent case for the 7mm-08) is almost improved in body taper. You would gain a little bit with the shoulder being straightened out.
As for fireforming .30-06 AI, it is really as simple as shooting regular .30-06 cartridges. They come out as AI. There is no need for fireforming loads as described.
At the moment I have a .280AI,a .25-06AI,and a .22-250AI.Velocity gains over the parent cartridge are not huge,but case trimming is almost a thing of the past!(I hate it!).As I have plenty of time on my hands and enjoy range time fireforming is not a problem,although I use Nosler brass in the .280AI.The Ackley chamberings are fun,and an easy way to get into wildcats.I don't consider time spent on dickin' around with rifles to be wasted time! Mur
I have one of those too. Nope, you don't gain much. - dan
notsorichguy
CGN Ultra frequent flyer
- Location
- The city that rhymes with fun
Or just get a neck sizer and don't size the shoulder......
I have a 257 Roberts Ackley Improved Lothar Walther light varmint barrel that I chambered and put on a VZ24 action. I has shot a 0.45" 5 shot group at 100m.
I also have a box stock Ruger #1V .223 that has shot a 0.46" 5 shot group at 100y.
I do not thing the Ackley improvement is worth the effort.
As pointed out above, the only shooters who gain a lot of velocity with the Ackley improved, are those who were following load books as limits, and their original loads had superfluous safety margins.
I also have a box stock Ruger #1V .223 that has shot a 0.46" 5 shot group at 100y.
I do not thing the Ackley improvement is worth the effort.
As pointed out above, the only shooters who gain a lot of velocity with the Ackley improved, are those who were following load books as limits, and their original loads had superfluous safety margins.
My Xbolt in 7WSM showed up yesterday, got it used off the EE. Just wondering about the 7-08 AI b/c I know someone who has one, and was telling me how it's really close to a 7mm Rem Mag
OK, let`s do the math. Whatever percentage you gain in case capacity when you improve the original case (given as a percentage, say 10% to make the math easier), you will get one quarter of that in velocity gains. So if your 248 whizzbang improved gets you 10% gain in case capacity, you 2.5% gain in velocity over an identical 248 whizzbang. There is no magic or alchemy involved in improved cases. Some will gain a great deal due to being older more tapered cases (250-3000 Savage and 300 H&H are usually the examples mentioned) to begin with. Some won`t gain very much as the design is fairly modern anyhow, with little body taper and relatively sharp shoulders already (308 Win and all it`s relatives for example). Anyone who is getting 7 Rem Mag velocities (or even near them) with a 7mm-08 AI is REALLY loading to high pressures. I fully support his right to do so, but I won`t stand near him at the firing line. I also wouldn`t buy a used gun off the guy. FWIW - dan
