IMO there are 3 major considerations about RF pressures in the Ballard (or in fact in any conversion):
Radial hoop pressure.
Breech block thrust.
Case wall blowout.
Hoop strength of the Redman/Brownell's liners is adequate for any of the above cartridges, by actual test, and especially with the added albeit minor assistance of the parent barrel's sleeve/hoop support.
Breech block thrust is greatly mitigated by the considerable mass of the block itself and the support of the wedge-locked block is entirely adequate for the RF pressures, again by repeated actual test.
The Ballard extractor is fairly easy to fit so that the case wall has full support even in the tiny unavoidable gaps where the extractor meets the cutaway chamber wall. Many other single shot rifles have more problematical designs; the Ballard is relatively pressure-tight & safe while the RF extractor parts are also, unfortunately, somewhat difficult to fab.
The 17 RFs apparently have a different pressure rise rate than the 22RFs since their use in the little Ruger 10/22 frequently requires a different-weight breechblock and a new mainspring. However, after doing several S/S rifle 17 RF conversions in both chamberings, I've found no problems.
The MAIN problem I've found with the 17s is that, when I shoot a squirrel anywhere except the head, then there's NOT ENOUGH LEFT TO EAT!(VBG)
Regards, Joe
