223 REM to 220 SWIFT?

[Riposte1]

I have only looked at one of these and, to be honest, I did not look closely at the extractor. I suspect it is much like the N.E.F. or other break open single shots.

The rim is not very pronounced on a .220 Swift so I would not think there would be much difference.

Your gunsmith will have to re-cut and re-temper the extractor or simply order up an extractor for replacement. I expect it is the same for either one as the 30-06, .243, etc. I am just guessing but I doubt they are much different between the 22/250 and the .220.

Either cartridge should do fine with the twist you mention, even to heavier bullets. Higher velocity usually works in your favor. I once had a custom Ingram Contender barrel in .221 Remington Fireball. I dont know the twist but it would not stabalize 50 gr. bullets. I rechambered it for .223 and it got markedly better but not great. I then improved the case and it got even better but still shot about 2.25 MOA. Finally I went to 22/250 and it got still better but not what I wanted out of a varmint gun and so I traded it off to someone who just wanted the oddity of a Contender Carbine (which was not a factory option then) .

Good luck with the project!

Riposte