I am getting a bit of leading with the gun. It starts in the forcing cone and seems to build if I fire a couple boxes. But it also has a trace of lead in the rifling down the bore. It brushes out with a reasonable amount of effort.
Both of my loads I've tried are 5 grains unique and either the RCBS 38-150-SWC or the Lee358-140-SWC. Both in special brass and with BAC lube. I've tried both ww alloy and a softer alloy, 50/50 ww/Pb I'd guess. Sizing them .358
I slugged the bore which is 5 grooves. Using a soda can shim the best I can figure it's .354. I've re-measured it and really tried to get a good feel and a light measurement. I can feel some change in the resistance when going through the area of the barrel where it threads into the frame. It's not a huge change though.
So I run as tight a fitted patch on a brass jag(didn't have a plastic one) as I could get started down the bore and it didn't get tighter at the threads. Now if I'm not mistaken Doug was suggesting this method with a plastic jag to feel for tightness. Will it not work with a brass jag or is the danger just getting the jag stuck?
I slugged just the muzzle by inserting a brass rod in the bore to tap the slug back out and it was .354 too. Seems small for a 357 bore, don't ya think? Is this common for Rugers? Looking back, I'm going to remeasure this.
I slugged the cylinders they all measure .3575. Yes all this with calipers as I don't have a micrometer.
So my query, Will sizing the bullets over throat diameter cause leading in of itself? Where should I go from here? Straight to having the throats opened up?
Should I buy a selection of pin gages? And if so, which sizes. Minus Z gages right?
Megasupermagnum has suggested I pull a bullet make sure it isn't being swaged down by the case which I will do.
Thanks for your help.
Bazoo