Thanks Daryl & DD, so is there no more to it than that, if it makes the bend I'm good to try it ?

I took the extractor out as I didn't want to change that yet, will that interfere with the loading when fitted ?

I was surprised it fitted with the 22LR breech block & much smaller/shallower groove or feed ramp.

I can fit the BSA 310 Cadet block into the 12/15 frame, saving me from converting to CF & gaining (if I need it) a much thicker & I expect stronger action & weight, if I need that ?

Then I can fit a 17HMR barrel I have to the Cadet & have the rimfire block work on that, surly the small amount from LR rim to Magnum rim would be Ok ?

Does the 38/55 have much recoil, I read on the forums people complaining of the 32/40 having to much recoil in the converted 310 Cadet configuration ?

Also I tried the 375Win shells I had first & bugger I needed to push those in by a tad, but when I found a couple of 38/55 shells they just slid in & fell out !