SiteLite SL-100 Laser Boresighter

Has anyone used one of these for initial scope alignment?

I just purchased one and it feels “overly” tight when I attempt to put it in my M4.

So much so that I don’t feel comfortable seating it.
I have considered oiling the O rings would make it easier to insert but…

I’d rather ask first than be sorry later.

Thx… Cliff

NVM… oil the O rings… major difference.