I know Swit Airsoft specialise in upgraded WW1 / WW2 era pews. Here's a link. Downside its in $ and its C02.
https://www.switairsoft.com/product-page/swit-custom-upgardes-mosin-nagant-m44-co2-bolt-action-rifle
OR
https://www.switairsoft.com/product-page/wg-mosin-nagant-co2-bolt-action-rifle
Cheers, @L3wisD
We're going through a big improvement stage at the moment in comparrison with the previous set up before it closed.
We're finding a reliable way of marking RIF's once theyve been chrono'd as welll. Currently using sticky tape but I understand this can quite easily be taken off...