Page 2 of Ackley Cartridge Article

[Jamie.270]

Page Two.  BTW, This was written by Bob Jourdan of the 6.5x55 BJ/Ackley improved fame

For the next best gain, number four in the chart provided, I am taking  my writer's prerogative to show a standard cartridge that Ackley did not work on, but is now known as the  6.5x55 BJ Ackley Improved, the initials  being my own. In the early 1990s I thought the standard 6.5x55 Swedish  cartridge would show nice gains if it were improved as an Ackley. Little did I know that Ackley never did it. But to make a long story  short, I got busy and copied the Ackley  design into the 6.5x55, with a great deal of input from Dave Manson of  Manson Reamers (PS advertiser). With the 140 gr. bullet the velocity  gain is 13.7%. Standard factory velocity is 2550 fps, while the 6.5x55  BJ Ackley gets 2900 fps. This is another Ackley cartridge that I have used extensively  for hunting, and I have heard from several readers who use it in long  range competitive shooting.

Fifth in the chart is a surprise – the .30-30 Ackley.  It shows a gain of 12.9% over the factory load with the 150 gr. bullet.  The factory shows a velocity of 2390 fps, and the Ackley can skip along at 2700, even from common  lever action rifles according to Mr. Ackley.  That just happens to be faster than the factory .300 Savage, and yet it  is the good old fashioned, century-old cartridge, improved.

Sixth best gain belongs to the 7x57mm Ackley.  Since we have properly verified loading information in the Speer #2  Manual, those are the figures we used and thus the Ackley beats the factory 7x57mm Mauser by  12.8%. The 7x57mm Ackley equals the  factory .270 Winchester and does so with 10 grs. less powder and less  recoil. Ackley said this cartridge has  the ideal capacity for a 7mm, and is powerful enough for all North  American big game hunting. I have friends who use this one, and it is  outstanding.

The seventh place round is another surprise to most shooters. It is the  .300 H&H Ackley Improved, with an  increase over the standard factory round of 11.1%. The factory loads the  .300 H&H with the 180 gr. bullet to 2880 fps, while the Ackley gives 3200. There have been a number of  improved .300 H&H cases, including the .300 Weatherby. They all  headspace on the case belt, so the case body can be blown out to most  any shape. Loads for the Ackley and the  Weatherby are the same. Ackley always  stated that these blown-out belted magnums are all badly over bore  capacity and greatly inefficient compared to the standard H&H.  Barrel life is short and faults far outweigh all good points, which seem  to be limited to perhaps better case life when headspaced on the  shoulder instead of the belt.

And now we arrive at number eight, the .257 Ackley  with a gain of 9.4% over the standard .257 Roberts load of 2650 fps  with the 117 gr. bullet. The Ackley gets  2900 fps with the same bullet. If we use the Winchester +P load of 2780  fps for the Roberts, the Ackley gain  drops to 4.3% and the cartridge is not worth chambering for. This shows  very plainly how poorly the factories have historically loaded the fine  .257 Roberts.

This takes care of the best eight Ackleys, in order, compared only to  standard factory loads and not with all bullet weights available. And we  must remember that every barrel gives different velocities, so those  listed here may vary from what other experimenters might achieve.

Now we will go to the other extreme, the poorest of the Ackleys. Ackley tested many cartridges that he knew  before he started would show poor results. But with so many shooters  asking about them, he felt obligated to prove just how inefficient they  might be. And in some situations the Improved case actually showed zero  gain! A good rule of thumb concerning Improved cartridges is that unless  the gain reaches a minimum of 6% the project is not worth doing.  Loading books often show peculiar numbers, some even appear to be  incorrect. An example would be when a book shows a top load for a heavy  bullet and then reduces the same powder when loading a lightweight  bullet. Since a lighter bullet can always utilize more powder, that book  value simply cannot be true. That is why experimenters with  chronographs find such interesting things.... Of course, there could be  extenuating circumstances that the book did not mention, but should  have.

The worst of the Ackley Improved  cartridges has captured last place in the chart, number 25, and is the  6mm Remington Ackley Improved with the  100 gr. bullet. The factory lists 3100 fps, and the top load found for  the Ackley is only 3200 fps. This is a  gain of just 3.2%, and is surely not worth going after. Even the 75 gr.  load shows a marginal gain, as we shall see.

From the bottom of the chart, holding down number 24 of the 25 listed  loads, is the .257 Ackley Improved when  compared to the.257 Roberts factory +P load of a 117 gr. bullet at 2780  fps. The Ackley only gains 4.3%, or up to  2900 fps. This is another Ackley round  not worth chambering for. Some books require close reading because they  list the standard .257 Roberts with a 22" barrel, while showing the .257  Ackley with a 26" barrel. Assume 25 fps  per inch of barrel and you have to remember to either add 100 fps to the  standard velocities, or subtract 100 fps from the Ackley readings in order to make a proper  comparison.

Tied with the .257 Ackley with +P  loadings in 24th place is the .260 Remington with a 140 gr. bullet  factory listed at 2760 fps. The .260 Remington Ackley  Improved sends the same bullet off at only 2880 fps, or just 4.3% gain.  This is well below the rule of thumb of a 6% minimum gain before making  a change to any particular Ackley. It  also is one that Ackley did not design as  such, but did work with as a wildcat cartridge back in his day, the  6.5mm-08.

The fourth worst is the .22-250 Ackley  with a 55 gr. bullet at 3850 fps. The factory .22-250 gets 3680 fps,  which means the Ackley only gains 4.6%  over the factory round. Here again, if we abide by our rule of thumb  when chambering for any Improved cartridge, we would have to pass on  this one.

Next on our list is one not too many shooters have interest in, the .375  H&H Ackley loaded with the 270 gr.  bullet. The factory .375 H&H sends that bullet off at 2690 fps,  while the Ackley gets 2830 fps, a gain of  5.2%.

The sixth cartridge of the less than desirable Ackleys is one from a  logjam of three, the 6mm Remington Ackley  with the 75 gr. bullet, as mentioned above. Here we find the standard  factory 6mm Remington sends off the 75 gr. bullet at 3400 fps, and the Ackley only gets 3600, for a gain of 5.9%.  This is close to the 6% required by our rule, so some shooters might  decide to chamber for this one. And this particular cartridge shows that  some cartridges are better with one weight of bullet than with another.  The 100 gr. in the Ackley is not good,  but this 75 gr. is perhaps acceptable.

Second out of the three-way logjam is the .220 Swift Ackley with a 50 gr. bullet at 4100 fps. This  is a 5.9% gain over the factory load of 3870 fps, and again, some  shooters might go for it. But there are other Ackleys that are better,  or at least more efficient. Historically, none of the Improved Swifts  have done very well, including the .220 Weatherby Rocket of days gone  by.

Third of the three-way tie is the 7mm-08 Remington Ackley with a 140 gr. bullet at 3030 fps. The  factory 7mm-08 gets 2860 from that bullet and the Ackley gain is again 5.9%. It is noteworthy  that this Ackley load outperforms the  factory .270 Winchester with the same bullet weight, and does so in a  short action.

Right on the borderline of our rule of thumb for getting involved in is  the old-time .219 Zipper, no longer being chambered for. The factory  load with a 55 gr. bullet is 3300 fps, and the Ackley  can achieve a velocity of 3500 fps, a gain of 6.0%. This is a rimmed  cartridge and just about obsolete, with very little demand.

This now leaves us with the so-called middle ground calibers. They are  all in the acceptable or better range of Ackleys, but of course some may  be a bit more desirable than others for various reasons. Some only make  the list with one particular bullet weight, or they make the list twice  in different positions due to bullet performance resulting in different  percentages of gain. Not all bullet weights are considered. The chart  will show details of this, so here we will only list the cartridge and  the gain, from best middle ground to worst. In gain order, the .270  Winchester Ackley, 8.8%; .25-06 Remington  Ackley, 8.4%; .375 H&H Ackley, 8.3%; .243 Winchester Ackley, 8.1%; .270 Winchester Ackley, 7.8%; .280 Remington Ackley, 7.7%; .30-06 Springfield Ackley, 7.4%; .30-06 Springfield Ackley, 6.5%.

As you can see, each of the Ackley  cartridges has its own story. It would fill a fat book to even begin  passing on all the stories, but maybe this information will be a start  for you. The chart with this will show all these Ackleys and their gains  in velocity. It should give your hot stove league plenty of grist for  another long winter.

Keep shooting, and hopefully with one of those Ackley  Improved cartridges.


Bob Jourdan
PS & TAR Staff

[gitano]

Jamie,
 
We're not ignoring this, we've all just been busy. It's a good idea. "We" should discuss it.
 
Paul