If there is any cartridge the chaps at Winchester would like to forget, it is probably the .225 Winchester. Had it's obituary appeared in the "New Haven Gazette" back in the 1960's, it might have read something like this: "Born in 1964 as a replacement for the .220 Swift, Died a victim of the .22-250."
Cartridge historians have long assumed that the design of the .225 cartridge was inspired by the .219 Zipper Improved. After all, the two cartridges look quite similar and the .225 even has a hint of rim at the rear of its case. The truth of the matter is, however, Winchester engineers had two time the .219 Wasp was still going strong in benchrest shooting circles and the .22-250 was the most popular high velocity twenty-two among serious varmint shooters. So, they designed a longer version of the Wasp, one capable of producing .22-250 velocities. And for the production purposes, the shoulder was decreased by about 5 degrees. The fact that the .225 ended up looking a bit like the .219 Zipper Improved was mere coincidence.
It is doubtful that Sherlock Holmes, Charlie Chan, and a pack of thoroughbred blood hounds could detect any difference in performance between the .225 Winchester and the .22-250, but the much older wildcat had such a head start, its domestication by Remington left the .225 gasping for air like a carp out of water. Still, the .225 Winchester is a great varmint cartridge and capable of incredible accuracy in a good rifle. The Winchester .225 factory load of 1960's vintage was some of the most accurate ammunition ever loaded, often clustering five shots into less than a minute of angle in a heavy barrel Model 70's.
If you own a rifle in .225 Winchester, simply load it with a good 55 grain bullet over H380, H4895, IMR-4895, IMR-4064, or RL-12, head for the varmint fields, and never look back.
The 225 Winchester was officially announced in June 1964. Both the standard and the heavier varmint version of the Model 70 bolt action were offered for this round. The 225 replaced the older 220 Swift in the Winchester line up. It was a rimmed case with an unusually large rim for this type of cartridge. The 220 Swift never achieved great popularity and neither did its replacement, the 225. The last Winchester catalog to list the cartridge as a caliber available for the Model 70 rifle was in 1972. No other manufacturer picked it up as a standard chambering because the already popular 22-250 was standardized by Remington less than a year later, and it was just common sense to adopt it instead. Winchester still loads 225 ammunition but this cartridge did not have a very long life, being obsolete in only 8 years.
The 225 is a fine varmint cartridge with performance similar to the 224 Weatherby or the 22-250 Remington. But the 22-250 was already established as a popular wildcat with an outstanding reputation, and it was inevitable that it would dominate the field. Those who purchased 225 Winchester rifles have no need to feel bad or trade them off for anything else because the 225 cartridge is just as accurate and will do anything that the more popular 22-250 will do. It simply turned out to be a design or idea whose time had not yet arrived. As a matter of fact, it might be well to hang on to your 255 because not a great many were sold and eventually some gun writer will rediscover it as the greatest 22 varmint cartridge conceived by the mind of man, and at that point all your shooting friends will wish they had one too. The 225 has an edge over the 222 and 223 Remington for long range varmint shooting because the increased muzzle velocity. At one time, Winchester was supposed to furnish a 50 grain loading at 3800 fps and a 60 grain at 3500 fps, along with the standard 55 grain at 3650 fps (now reduced to 3570 fps), but these loads never materialized. For handloaders, this cartridge is nothing more than a slightly modified 30-30. Neck down a 30-30 to 22 caliber, shorten the case slightly, turn the rim to '06 dimensions and slightly improve and you have the 225 Winchester.