There are certain cartridge cases that just beg to be "improved". One of them is definitely the 220 Swift.
I looked at a really nice older Sako Varmint model 220 Swift a few months ago. It was in like new condition but I cheaped out and ended up not buying it. As is par for the course, now I'm regretting not buying it.
Same thing happened to me 6 or 7 years ago.
Local gun shop had a "used" but looked brand spanking new BRNO 602 in 375 H&H Mag. for $ 1,000 Canadian pesos. I didn't buy it that day. I came back 7 days later with money in hand with the idea of having it Ackley Improved.
Walked in the LGS with a smile on my face only to be told it sold yesterday !!!
This rifle for sure had no more than 1 box of ammo through it. I'd swear it was new if the salesman didn't tell me it was a used rifle.
I will regret not buying it right away for the rest of my life. And I don't even have any use for anything that powerful.
