Krh1326
11-26-2022, 12:23 PM
I don’t do alot of 9mm casting. I had one 9mm ( P938 ) in the collection. I did NOT do my homework, and slug the barrel. I skimmed these forums , and took an educated guess at sizing to .357
This worked great in P938. My favorite boolit is a Hollow Pointed TC NOE version of Lee’s 124 gr TC.
Chambers flawlessly, and never leading of barrel ( I do powder coat, gas check and lube … I have the time and patience…. Why not? )
I recently acquired a Sig P229 9mm Emperor Scorpion… brandy spanking new, old stock.
I decided to sit down with it, and do my homework. I broke it down, casted up some beauty .359 HPTCs. I just tapped one thru the lubed barrel and I got a groove diameter of .3545-.355
Starting at .359 as cast, that slug didn’t show any real signs of heavy lead distortion or displacement, other than the obvious rifling grooves.
If I use the +.001 method , that would have me size at .356 Is that enough?
I would rather size for my, now two, 9mm’s , the same .357 , as well as load the same ( 4.2 gr HP-38 ) for both, just for simplicity, on my part.
As long as .357 chambers, and I don’t lead, would it make any functional difference being on the large size? For that matter, if I sized everything at .358 ( providing they both chamber and don’t lead ) would that make any functional difference?
This worked great in P938. My favorite boolit is a Hollow Pointed TC NOE version of Lee’s 124 gr TC.
Chambers flawlessly, and never leading of barrel ( I do powder coat, gas check and lube … I have the time and patience…. Why not? )
I recently acquired a Sig P229 9mm Emperor Scorpion… brandy spanking new, old stock.
I decided to sit down with it, and do my homework. I broke it down, casted up some beauty .359 HPTCs. I just tapped one thru the lubed barrel and I got a groove diameter of .3545-.355
Starting at .359 as cast, that slug didn’t show any real signs of heavy lead distortion or displacement, other than the obvious rifling grooves.
If I use the +.001 method , that would have me size at .356 Is that enough?
I would rather size for my, now two, 9mm’s , the same .357 , as well as load the same ( 4.2 gr HP-38 ) for both, just for simplicity, on my part.
As long as .357 chambers, and I don’t lead, would it make any functional difference being on the large size? For that matter, if I sized everything at .358 ( providing they both chamber and don’t lead ) would that make any functional difference?