The .35 Whelan is one of my favorite rounds. I have two. One an expensive custom job on an Oberndorf Mauser and the other a Ruger Mod. 77RS in a Ramline synthetic stock.
However, finding a rifle in .35 Whelan may be a bit difficult nowadays. Ruger made only a few,and Remington has dropped the rifles from production. You can still get one through the custom shop, I think. The only other alternatives are a special order gun from Winchester at an exhorbitant price, or buy a 30-06 and have it rebarreled. You might get lucky and find one at a gun show. That's how I found my Ruger. I wish you luck.
Only Remington and Federal make ammo for the .35 Whelan, (dammit!) Supposedly Remington loads it with 200 gr. and 250 gr. bullets. I can't find any 250's to save my life, and the local dealers here are reluctant to stock even the 200 gr. loads. Federal only loads the 225 gr. bullet with a premium style bullet. Plenty of those around, but I'm not willing to pay their price. I reload.
If I had the choice of the regular .35 Whelan or the Ackely version, I'd stick with the regular version. I have an article in, I believe a RIFLE Magazine, where the author had the .35 Whelan, then improved it. He then tried the Brown improved Whelan, but felt it was too much work making up the brass for it. He said if he had to do it all over again, he'd stick with the original .35 Whelan. I agree whole heartedly.
Let's look at the pros and cons. The regular has factory ammo, albeit, somewhat limited. The Ackely version has to be fireformed to get brass. Secondly, it is a wildcat round, making it a difficult gun to sell, if need be. Dies to reload are a bit more expensive as well. The Brown-Whelan need some extra dies to form which are expensive. You have to first neck the case up to about .40 caliber, then size the neck back down, leaving a .40 caliber shoulder to headspace the round, just to fireform it. A real pain in the posterior region. The remarks about being a wildcat also apply here as well.
For some reason, the American shooter has not taken to the .35 caliber rifles, with the exception of the .35 Remington. Look at the .358 Win. for example, or the scarcity of .35 Whelan rifles and ammo, or the .358 Norma Magnum.
Just for the record, I use 200 gr. bullets in the .358 Win. and 250 gr. bullets in the Whelan. With Remington factory, my Ruger will put 3 shots into one inch with the 250 gr. bullet and 1.25 inch with the 200 gr bullet. Mix them up and the group is 1.5 inches, so I don't have to resight in if I should have to change bullets. My custom job is not so democratic.
If you go to a .35 Whelan, I think you'll be happy. Recoil is a bit more than the 30-06 with the heavier bullets but not bad. The 200 gr. bullets will work well on deer sized game, and the 250's on bigger animals. In fact, it should work on any "critter" on the North American continent and most of African game as well.
JMHO.
Paul B.