Whilst performing the crowning operation is GENERALLY best done on the lathe (where a ham fisted non-caring operator can really ruin things quickly),I fail to see what's wrong w/ roughing out the crown w the deburring tool and then finishing w/ the lapping balls or similar, in certain situations, such as this SKS. It just depends on the person doing the work. A careful and observant craftsman can easily make a good and servicable crown w/o a lathe. In actual fact, I've had to retreat from the piloted Brownell's tool to a less "precise" cutter on more than one occasion to achieve proper results. Again if the edges are cleanly broken and the chamfer is visibly centered to the bore, the end result will be the same, unless we're trying to go sub-1/2 MOA.
The recess is for protection from dings, and the bore should end in an even manner, that's it. All the rest is more or less "eyewash".
As far as the "horror" of hand tools goes, I've bored out and recut the rifling in my family heirloom squirrel rifle completely by hand, as the initial results on the lathe were wretched. 42" of hand bored and hand cut rifling that is accurate enough to take squirrels (1 to 1 1/2lb greys, big fox squirrels are rare around here) at 50yds w/ teeny iron sights- if the nut behind the trigger does his part!
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I'm done, and I think Hylander is done except for some cosmetic enhancements, so have at it!
ETA: OK, I'm not quite done. I think Hylander should have shot the rifle before doing anything else, as noted in my first post. At least establish a baseline. I've a No.4 Mk.1 that has a factory crown which was so quickly done in '43 that it looks threaded (and DEEP too!) and it manages 3 MOA, sometimes 2- 2 1/2MOA. My first L42a1 has pits in the crown which have worried me since 1994 or 5, but it still shoots sub-MOA, sometime really sub, off the bench w/ 155 sierras. Would a pretty crown help either of those two? Not bl**&y much, I reckon!
