The bolt might be a replacement for a lost original assembly.
A standard 30-06 bolt will work,or one from a 270. Two common M70 calibers.
The case head size on the 220Swift is 30-06 size,,the case body slightly smaller in dia leaving it with it's semi-rim case.
Perhaps a replacement bolt with it's non-matching ser# to the Swifts recv'r # simply had the bolt number polished off.
Better looking as a -blank- than a mismatched part.
The ejector in the 220Swift M70 is a longer length than the standard ejector used in the 30-06/270 calibers
due to the shorter 220S case length. Same one used in the 257Roberts and 243.
The mag box is shorter than the standard 30-06 box .
