Can you shoot your rifle at a rifle range with conventional ammo, but in the field monos only?
As long as the monos are of the Woodleigh Hydro design you won't have pressure issues, use conventional loads from starting loads & work up, again its a try & see what works for regulation in your particular rifle.
It took 4 powders to regulate my merkel with woodleighs!

Yes they are available
https://www.woodleighbullets.com.au/bullet-lists/hydrostatically-stabilised

English stockists

KYNAMCO (Pvt) LIMITED The Old Railway Station, Station Road,
Mildenhall, SUFFOLK, ENGLAND, IP28 7DT
Ph. 44 163 871 1799 Fax. 44 163 851 5251
www.kynamco.co.uk
sales@kynamco.co.uk

RELOADING SOLUTIONS
6 Cherwell Business Centre Rowles Way KIDLINGTON UK 0X51LA
Ph. 44 186 537 8200
sales@reloadingsolutions.com

Best of luck mate, you are dealing with a great calibre! - keep us informed