Bullet sizing from .359 mold casting

Want to experiment using a 38/357 mold that casts at .359 and using the bullets is a 9mm revolver. Would sizing them to .356 or .357 be acceptable? 

Thanks

Most US 9mm have .357 groove, check your barrel first

bruce martindale wrote:Most US 9mm have .357 groove, check your barrel first

Using that Lothar Walther .355 barrel stock,  concerned with the sizing question for now. Thanks

Should be no problem.  When sizing down just need to retain about .005 lube groove depth.

Cylinder throat diameter is a factor as well. You don't want any clearance there. The barrel will size them down.

Worst case is cylinder throats smaller than the barrel. I've got, or had, a couple like that. 'Lead Mines'.

Look at posts #2, 3 & 7 here:  
https://castboolits.gunloads.com/showthread.php?21598-A-beginner-s-guide-to-revolver-accuracy  

The best way to measure revolver cylinder throat diameters is with a pin gauge, which are available.  You will get surprises, most of them unpleasant.

NuJudge wrote:Look at posts #2, 3 & 7 here:  
https://castboolits.gunloads.com/showthread.php?21598-A-beginner-s-guide-to-revolver-accuracy  

The best way to measure revolver cylinder throat diameters is with a pin gauge, which are available.  You will get surprises, most of them unpleasant.

RE: My S&W 986 L frame 9mm revolver

My pin gauges indicate .358 cylinder diameter. Replaced the factory 9mm revolver barrel (which are .357/358) with the Lothar Walthers .355 barrel. From what I have been told the Walther designed rifling (.355) will adapt with lead bullets from .355 to .358.  But .001 over bore would be a starting point.

One more problem I have with one pistol, a 9mm Browning HiPower.  It has a tight chamber, but loose groove diameter.  If I seat a bullet big enough to fill the grooves in a case, the assembled cartridge will not fit in the chamber.  

You can see if this problem exists by slightly belling a fired case, and seeing if a bullet will slip in the case.