In the absence of low pressure reloads there is at least one commercially available load that I would not hesitate using in it continually. That is the B & P Comp One load, a 1 oz. load that has chamber pressure in the lower 8000 psi range, as I recall. Very mild recoil and velocity listed at 1160 which, IMHO, may be very nearly the perfect velocity for best patterning of target and upland birds. For even less stress on the old wood they offer a 7/8 oz. load as well.

https://baschieri-pellagriusa.com/competition/competition-one/

[Linked Image from jpgbox.com]