Well, 2 days of constant testing and about 500 rounds used. Beforehand, I reamed the cylinder throats by hand to .357 with a Manson reamer ordered through Brownells - so it has to be good. I used 2.7 Vihtavouri 310 with a variety of .357 HBWC including some Hornady, some H&N from Germany and locally made smooth sided HBWC's with Allox lube. My results were quite disappointing. Using a 6 X 32 scope at 25 metres and sandbagging failed to achieve that one hole group. Leading was still evident but not detrimental to accuracy. Remember this is down a .3545 barrel.
The next day I dispensed with the scope and went to an Aristocrat sight with 3 position. I went to 2.9 of V310 and introduced 2.9 Bullseye I also had some .356 HBWC with the above load. I also had some .358 DBBWC hard cast in .38 cases and magnum cases with 3.8 Bullseye.
Knock me down with a feather!! 40 rounds of the 2.9 of 310 and Bullseye produced 40 X rings out of 40 shots at 25 metres, the best group coming from using the .356 heads. Should I go down to .355 heads bearing in mind I have .357 cylinder throats.
The 3.8 Bullseye in either the 38 or magnum case with the DBBWC still held the X ring, the best from magnum cases.
These rounds as immediately above (3.8 etc) proved the best at 50 metres, probably enough to hold the 10 ring.
So whats going on? I'm getting results contrary to all my previous experience with the hard cast Double Bevel Base WC's, ostensibly a solid slug of hard lead.
The 1 in 10 twist barrel I'm using seems very good at 25 but in contrast lacking at 50. Am I being too fussy. Should I switch to a 1 in 12 or 1 in 14 as a compromise. The PPC is based on a 686.
Over to you most knowledgeable chaps for some more of your most interesting comments.
By the way, the weather did hold, but went to rain during the last hour of testing.