Bullet size to throat

[Tad Houston]

I slugged the barrel and throat in my .41 mag tracker and i got .411 for the barrel and .412 for the throat. Should i use .412
lead bullets? i just got some Oregon trail SWC at .412 and the bullet will fit in the throat of the cylinder, but it is a pretty tight fit. I was just a little worried about pressure.  Thanks-Tad

[HWooldridge]

Depends on the load and type of alloy.  I shoot a 200gr linotype bullet sized .4515 in a Ruger 45 LC that averages a  .453 cyl throat and the bore mikes .451.  These rounds shoot quite well - much better than I can hold.  I doubt you will have any pressure issues with the dimensions you are getting assuming any reasonable load.  More importantly, can you chamber a loaded round easily without having to hammer it in?

[richp41]

Match the throat diameter as closely as possible. Magnum loads will generate enough presure to cause the bullets to obturate  in the cylinder whereas light loads will not. Without a good seal around the bullet, the gases will cause flame cutting of the bullet and leading. Lead bullets will swage down in the barrel throat and will not cause any major degree of pressure increases. Rich