Be careful.....220 russian brass is thicker in the necks than the sako/norma usa brass. I have a way of checking USA chambers. Here is one way to do it.
One, FL a 220 russian, long seat a lubed bullet(dummy round) (this is for killing two birds with one stone) then take a black magic marker and cover the neck of the brass. Chamber it. The bullet should be pushed back into the case to show Jam length, plus, take a look at the mark on the neck and see if it is being rubbed off any around the circuferance. If everything looks good, seat the bullet .005 deaper (same unloaded round). put another coating of marker on it and chamber again, it should chamber easier this time. Check for rubbing again around neck. If everything is ok that time. Load a round with a low charge of powder (like 27.0 grains of V133) and shoot it. With the shot brass, see if a bullet will slide in the neck. You do not want to have to push it into the neck, if it slides in with a little sloppiness, your good to go, if you have to push it in the neck, then your going to have to neck turn just a little off. If you see rub marks around the neck above, you have to neck turn a little.
There is also another a couple of other ways. 1. make a chambe cast 2. fireform WITHOUT a bullet and using pistol powder a couple of times with the same case, then see if a bullet will slide in the neck. This can be a dangerous method if you are not experienced or know what your doing.
Hovis