Q: Once again I find myself writing to you for technical advice. I have an old .30-30 rifle that was rebarreled in .219 Zipper some years back. I am considering having this barrel rechambered to .219 Zipper Ackley Improved. Please find data for this cartridge taken from P.O Ackley’s Handbook for Shooters and Reloaders. Can you supply additional information about this improved calibre? Do you know of a gunsmith who has a reamer for the .219 Zipper Improved who would undertake this project? What extra steps are involved in forming cases for this wildcat? Can standard .219 Zipper cases be fireformed to fit the Ackley chamber? I would like to purchase a .219 Zipper Ackley Improved die set. Do you know of company that manufactures them?
A: For a start, you didn’t tell me what kind of rifle you have in .219 Zipper? I think it may be a Winchester Model 94. If so, you could have it rechambered to the .219 Zipper Improved, but the only advantage would be less backthrust against the bolt face. You wouldn’t gain much velocity as loads have to be reduced to be safe in a lever action. It may also require some gunsmithing to get the fatter cartridges to feed through the action.
P.O Ackley’s Handbook for Shooters and Reloaders (2 volumes) is an interesting read, but contains a lot of dangerous load data. I’ve checked some of those loads and several listed as maximum would blow a rifle up. Back in those days few experimenters owned chronographs or pressure measuring equipment, so many of the velocities are guesstimated, The velocities listed for the .219 Zipper Improved would strain the .220 Swift Improved. As a rough guess you could deduct 300fps from them, since the loads in Ackley’s book were supposedly taken in a single shot rifle. User of lever-actions have to keep their loads moderate, or mild enough to enable easy fired case extraction.
I don’t know of a gunsmith who has a reamer for the .219 Zipper Improved. Cases can be fireformed. But it would involve a fair amount of work to make cases from .30-30 cases. RCBS used to list .219 Zipper Improved case forming dies and a file-and-trim die to resize and trim .30-30 cases. After this they must be fireformed with a moderate load then trimmed again. You may also have to ream the necks depending on the chamber in the rifle, but even if no trimming is needed, it is best to line-ream the cases for better accuracy. C-H Precision could be a good bet for a die set.
For your information: originally the .219 Zipper was loaded with a .224″ 56gn bullet at 3110fps. The nominal working pressure was 38,000 psi to be safe in leverguns. This could be increased to 50,000 psi in a strong falling block action with velocities equalling the .22-250 e.g50gn bullet at 3600fps; 55gn bullet at 3450fps.
The .219 Zipper is a fine cartridge, no doubt about it, but the .225 Winchester, except for being smaller and having a thinner rim is the spittin” image of Ackley’s old wildcat. If your rifle is a lever action I’d forget about having it rechambered, but if it is a strong single shot, the Zipper Improved may be worthwhile.