There is no longer any advantage to tight bores, despite the use by the Canadian Palma Team. We have the Krieger tight bore, Canadian Palma-spec barrels in stock, but don't recommend them. We have also done lots of research and consulted with Johnnie Marshal, Alain Marion, Nammo Lapua Oy, Krieger, top gunsmiths and many others and none of the above recommend tight bores. Common knowledge is that tigher bores were developed for undersize military bullets and this is no longer necessary. TR shooter Mike Wong Shui ordered one, in case he had to shoot issued ammo.
RPA may be a TR standard, but it is worthwhile to look at top international FClass results and talk to the very best of gunsmiths world-wide to see choices and ask which actions have the best tolerances.
Definetly worthwhile talking to Paul Reibin, who by the way does not advise using tight bores for TR.
Regards,
Peter