Originally Posted by
Bruce_in_Oz
A couple of "issues" here;
The original No4 bedding was done to tune the rifle to Cordite-fueled Mk Vll ball, not Mk8z
Is the barrel a standard, unmodified No4 barrel?
Is the "new" fore-end an original, a Kosher repro or "unknown"?
Range shooters do some very odd and sometimes dangerous things to these rifle, in a wild pursuit of more "possibles". Sometimes it's bit like; "Another wafer, Mr. Creosote?"
IF you have a MINT, original military barrel and exclusively use your pallet of Mk8z, you can do your own thing, but it might take a fair few rounds, a bit of barrel life and a lot of fiddling with woodwork to get the desired result. Or, you might chance on the magic formula tomorrow.
Has the new fore-end been correctly seated on the draws and on the barrel reinforce / Knox form?
Every time you remove the fore-end and "do something" to it,and then refit it, your "zero" WILL shift, whilst the groups may get smaller, or not. If the timber is not totally stable, evil things will happen to your grouping AND MPI every time the weather changes: hot, cold, wet, dry. If you also keep fiddling with the ammo as the seasons and conditions change, it will get untidy.
That is why all the original fore-end timber was selected for straightness of grain and grain cross section, the "rough" blank, that had been curing for several years, was cut to a "flitch' which was a slightly over-length chunk, not a lot bigger in cross section than the desired finish shape, stored in a climate-controlled place for a a few more months, to stabilize and only THEN, fed into the machinery to cut away any bits that did not look like a fore-end.
Some of these time-frames were "abbreviated" in WW2, but as far as I know, no steps were omitted entirely. This, and the "interesting" challenges posed by conditions in the event of Nuclear, Biological and Chemical warfare drove the shift to moulded, synthetic furniture on small arms. Steam cleaning a timber-stocked No4, or any wood-bearing small arm, for that matter, does interesting things to the furniture. "Chassis" systems, like the Accuracy International AW, etc. are a further step away from timber furniture.