question on lower bolt rails

[gradywhite]

i was wondering who has the lower bolt rails for sale for 7.62 and 5.45 besides K-var(only have 5.45s listed)?
also are the bolt rails ,shall i say, universal? meaning will 7.62 rails work in a 5.45 and vica-versa? will romanian 5.45 rails work in a bulgarian 5.45 kit and vica-versa?
thanks

[ar15junkie]

I just used a set of 7.62 rails from kvar on mine. They needed to be trimmed back on the lower mag rails and the extractor was a little long.