Originally Posted by c_brutsche
Just out of curiosity, how far deep past the + or - .005" can you seat a bullet. I never had a problem with this but just out of curiosity, how far deep would you have to go to possibly result in a kaboom. I have accidently seated my .45 colt cartridge projectiles around - .007-.008" and shot them with no problems in my ruger blackhawk. Just curious about the kaboom stories I have read about.
Plus or minus .005" is nothing to be concerned about, particularly with 45 colt.
The thing is that powders ordinarily behave in a predictable fashion. Notice "ORDINARILY". When used according to recognized published relaoding data.
Having the powders confined in the case, behind the bullet when ignited, causes a predictable rise in temperature and pressure of the expanding gasses. This rise in temperature and pressure also has a "time" component. Kind of imagine a graph, with the X coordinates being the temp/pressure, and the Y as time. When you decrease the internal volume of the case behind the bullet, the temp/pressure will rise quicker, generally. (Remember, I'm speaking "IN GENERAL" for all this). When temperature rises, burning accelerates. When pressure rises, burning (time) accelerates. When time accelerates, both pressure and temperature rise accordingly. So if you confine things too tightly, you get "KaBOOM!" More powder makes for more heat and more pressure and it all happens in a finite amount of time.
The object is to extract the maximum energy from the powder, while keeping the pressure below the safe limits. And to have it happen in a length of time that will propel the bullet at a maximum velocity for the amount of powder expended, given the barrel length of the firearm.
Reloading is safe and reasonable, and very predictable, when you keep within the published limits. Seating the 45 Colt slug .008" deeper will not reduce the case volume appreciably (figure the percentage of volume, here). But on other things like maybe 9mm, .040" is a significant percentage.