Catpop
Member
This is how I find it after extensive testing with 357 RUGER Blackhawk and 44 mag RUGER Super Blackhawk. Notice I said I because this is from MY actual range result.
FIRST Groove fit
-Barrel leading disappears when boolit is .003 over groove diameter.
-Barrel leading is minimal and quickly removed with bore brush or same wrapped in chore boy bronze wool when boolit is .002 over groove diameter
-Barrel leading is a BEAR requiring many applications of chore boy with .001 or less over groove diameter.
SECOND throat fit
That said, we get to cylinder throat diameter
-throat diameter should be same size as boolit diameter. Or at most a hair over, say .0001 over. Finger push through is excellent.
THIRD cartridge fit
-cartridge must reliably fit all chambers of revolver!!!!! The last thing you need is the most accurate load in the world that you can't chamber!!!!!
All that said, boolit hardness and lubes come into play as lead boolit fps increase but basically not at target load velocity.
And that how I find it!
Additional info
I have 1973 357 bh that came with a .359 groove diameter and .358 throats- so every lead round fired swagged the boolit to under groove diameter. You see the leading that was causing!!!!
It now has .361 throats and shoots .361 with very minimal leading. It shoots .362 with no leading, but won't chamber 50% of rounds. So that's the end of that quest and I have a bh that's good only for jacketed bullets or a trip to choreboy town.
I have also been testing my new in box 2016 RUGER superblackhawk and found it came with .429 groove (they got that right) and .4315 throats (which I thought was good). Testing reveals .430 Missouri leads very badly, .431 Montana also leads but less badly, but hm .433 sized down to .432 offer only minimal leading.
Remember the .4315 throat it came with? So every boolit even though sized to .432 is actually being resized to .4315 on firing. So thats a brick wall on a factory new unmodified and still in warranty revolver.
I called RUGER yesterday and to make a long story short, was told in was in spec at Rugers tolerances of .4315 to .432. So NO help there! Yea I tired to get him to commit to bringing it up to .432, but to no avail. They were nice, but firm!
All this is actual hands on and may it will help you if you too experience lead boolit l adding issues with factory or hmm boolits
FIRST Groove fit
-Barrel leading disappears when boolit is .003 over groove diameter.
-Barrel leading is minimal and quickly removed with bore brush or same wrapped in chore boy bronze wool when boolit is .002 over groove diameter
-Barrel leading is a BEAR requiring many applications of chore boy with .001 or less over groove diameter.
SECOND throat fit
That said, we get to cylinder throat diameter
-throat diameter should be same size as boolit diameter. Or at most a hair over, say .0001 over. Finger push through is excellent.
THIRD cartridge fit
-cartridge must reliably fit all chambers of revolver!!!!! The last thing you need is the most accurate load in the world that you can't chamber!!!!!
All that said, boolit hardness and lubes come into play as lead boolit fps increase but basically not at target load velocity.
And that how I find it!
Additional info
I have 1973 357 bh that came with a .359 groove diameter and .358 throats- so every lead round fired swagged the boolit to under groove diameter. You see the leading that was causing!!!!
It now has .361 throats and shoots .361 with very minimal leading. It shoots .362 with no leading, but won't chamber 50% of rounds. So that's the end of that quest and I have a bh that's good only for jacketed bullets or a trip to choreboy town.
I have also been testing my new in box 2016 RUGER superblackhawk and found it came with .429 groove (they got that right) and .4315 throats (which I thought was good). Testing reveals .430 Missouri leads very badly, .431 Montana also leads but less badly, but hm .433 sized down to .432 offer only minimal leading.
Remember the .4315 throat it came with? So every boolit even though sized to .432 is actually being resized to .4315 on firing. So thats a brick wall on a factory new unmodified and still in warranty revolver.
I called RUGER yesterday and to make a long story short, was told in was in spec at Rugers tolerances of .4315 to .432. So NO help there! Yea I tired to get him to commit to bringing it up to .432, but to no avail. They were nice, but firm!
All this is actual hands on and may it will help you if you too experience lead boolit l adding issues with factory or hmm boolits