Relatively inexpensive, $150-$200. You thenhave to fireform your cases, buy a set of Ackley dies ( usually a regular 30-30 Lee FCD will work. You will need a chornograph, otherwise it's very, very easy to end up with loads that generate prohibitive pressures ( 50,000 easy!) You can expect around 100-200 fps more velocity than you are getting now, and they can be very finicky to load. I played with one awhile, learned alot, like it, but you gain nothing over a 24" standard 30-30. However, the litle Ackley cases is "cute", is something different, and works best with heavy bullets, at least mine did. I personally would not do it again, but I don't regret it. I just fulfilled my "need for speed" with a 308MXLR. I love the 30-30 "as is", and will most likely get another 336RC soon. Good luck to you!
I had an H&R single shot 30-30 taken out to Ackley Improved. You can still fire new 30-30 ammo in it. It will then fire form the brass. I do not recommend you use brass that you have fired a lot as there is a chance it might split during the expanding stage. The kicker was the price of a set of reloading dies. Unless you find a used set (might run an ad on this site) the cost is stout. I honestly did not find the experience worth the cost as the gains were not too great. I shoot cast and they might be better with jacketed. After about a year I had the barrel reworked again, this time going to 30-40 Krag. Best part is brass and dies are available and you can make brass from 303 British in a pinch. Good luck either way you go. Shenandoah
As per Sam Fadala in his book on the .30-30, he had his customized Winchester 94 bored out to the Improved configuration not to increase velocity but to extend case life. Improved cartridges don't have nearly as much brass flow than the very tapered standard .30-30 cases, so brass lasts a good deal longer with multiple reloadings. I've got a number of .30-30's, so I'm considering having one of them bored out to the Ackley Improved configuration just for the heck of it.