I have a set of lee dies that I tried on Lapua brass. It does not chamber the same as when the brass was new. I have noticed that the american brass has different dimensions, should I be using euro dies?

I couldn't say for sure if there are dimensional differences in American vs European dies. There shouldn't be any, I use American made dies on European produced 6,5x55's with zero problems.
I would however suggest investing in dies other than Lee. IMHO RCBS, Forster or Redding dies are superior in quality and function to Lee dies...................DJ

A year or so ago on this forum there was an interesting discussion on the 6.5x55.The American brass head diameter is that of the 30-06 family [.473 ] , the european is .480.There are other small differences depending on which european version , Norwegian or Swedish military etc. In any case the latest ,to get everyone on the same track, is the 6.5x55 SE.You would have to find what the chamber is cut to and what the cases are formed to.

I use Redding dies and lapua and norma brass.

I only neck size also.

quote:

Originally posted by GSP7:
I use Redding dies and lapua and norma brass.

I only neck size also.

Ditto, mostly. Redding dies, Lapua brass, neck size after first firing. No issues.

No mention is made of your rifle. The Swede military rifles have much longer headspace than my M70 Win.
It is not uncommon to have a minimum headspace rifle refuse reloaded ammo. Some presses have a lot of spring and do not size the case as well as they should. You can over come this many times by partially withdrawing the case from the sizer and rotating it, then resizing it again.