Worry much more about fit in the cylinder throats than the bore. And, that old belief that harder is better is just not true. A BHN of 10-12 works great when they fit the throats.
Worry much more about fit in the cylinder throats than the bore. And, that old belief that harder is better is just not true. A BHN of 10-12 works great when they fit the throats.
Regional Government Sales Manager for Aimpoint, Inc. USA
Co-owner Hardwired Tactical Shooting (HiTS)
To be honest, I don't really worry much about lead hardness. I use wheel weights and *might* water quench ones I know are going into a magnum handgun or rifle load. I focus more on fit to the gun in question, which is why I have a pile of pin gauges for 32, 38, 44, and 45 calibers.
That's not to say it isn't important, just that I haven't reached a level where it is a factor for me and my shooting. That said, I'm about to embark on serious cast bullet work for my 35 Whelen, so I may find myself working with the alloy and hardness more than previously. In my revolvers, I get the results I'm after by focusing on bullet quality (going about the casting process properly) and using a size appropriate to the gun.
Both articles are good sources of information. Glenn Fryxell in particular is a great source of info about casting.
Chris
@mtnbkr and @Wayne Dobbs thanks for expanding my understanding of this
One more question, what do I measure in a semi auto's barrel to pick the correct bullet diameter?
Last edited by Alpha Sierra; 02-12-2019 at 12:02 PM.
Ideally the throat just ahead of the chamber. But....sometimes that is hard to precisely measure and if you do get a measurement and size cast bullets accordingly, you can't get the rounds to chamber. Bullet fit vs gun dimensions are sometimes hard to mate up. There is a guy on Cast Boolits Forum, by the handle of DougGuy that runs a business in which he reams/uniforms cylinders and chamber/throats to make guns much more accurate and consistent with any bullets, but particularly cast ones.
Regional Government Sales Manager for Aimpoint, Inc. USA
Co-owner Hardwired Tactical Shooting (HiTS)
My pleasure.
For semi-autos, slug the barrel by driving a dead soft lead ball through the barrel, then measure the slug. That said, with a semi, you have fewer variables (no cylinder with multiple throats for example), so you can get where you need to go with experimentation if you aren't prepared to measure directly.
Chris
When I was shooting SSR in IDPA with the 125 power factor, I went through thousands of Zero swaged RNLs over a max load of Titegroup in my M67 at ~830 fps. I did a class where I went through >700 rounds in one day, only occasionally brushing out the chambers. No leading whatsoever, but it took a lot of elbow grease, BreakFree and 0000 steel wool to get the black off the outside of the cylinder.