choosing revolver lead bullet diameter

[oley55]

I have a Ruger RH, 44mag, 7.5" barrel. after re-slugging too damn many times, I am reasonably confident in these measurements.

cylinder throats slugged at .4327-.4328".
barrel slugged .4300-.4301".

based forum information I have read, my bullets should be sized to the cylinder throat size and should pass through with light pressure.

looking at different sources, I found Beartooth sells .44 lead sized to: .429", .430", .4315", and .432". https://beartoothbullets.com/bulletselect/index.htm

based on throat diameters, .432" is the closest I can get, but they will very likely fall through the throats.

Am I slipping into the custom mold and sizing die world?
If so, how much difference in diameter from cylinder throat to barrel can I safely shoot?
And finally is this particular RH basically a jacketed bullet only firearm?

[jepp2]

based forum information I have read, my bullets should be sized to the cylinder throat size and should pass through with light pressure.

That is ideal, but not absolutely necessary. My own priority system is:
#! throats MUST be larger than the groove diameter
#2 bullets must be larger than the groove diameter
#3 match the hardness to your desired peak pressure

After that, everything else is significantly less important. Your fine on the throats being larger. I would try the .432" bullets and I wouldn't expect them to fall through the throats. But even if they do, they will bump up in diameter when fired.

Don't shoot a hard bullet too slow! That is a problem. Know the BHN of what you are buying.

[oley55]

thanks Jepp2.

I must be a bit OCD or something because I keep getting myself wrapped around the axle.

[chiefr]

If in doubt you can always slug your bore. My SW44 mag likes bullets sized to .429 so I size to .429. Bullets sized at .430 tend to lead and accuracy suffers.

Having said that, I used to own a Ruger SBH, that liked bullets sized to .430.

If accuracy is your goal, experiment and see what's best for your pistol.

[oley55]

I have also pin gauged; .432" (.4319") will pass thru all six cylinders. 3 of those are slightly tight but they still go thru without force. the .433 (.4329") will not even start in any of the cylinders. note: the ( ) number is my micrometer measurement of the pins.

Frankly I was thinking slugging would be more accurate, but now that I think about it, spring back is likely giving me the .0007-.0008 bump.

so it looks like a modest purchase of .432s for a trial run.

[jepp2]

but now that I think about it, spring back is likely giving me the .0007-.0008 bump.

I don't know what you used to slug with. I get the best results using pure lead muzzleloader balls. Using those you shouldn't get spring back.

Keep in mind that your pin gages only tell you the minor diameter, not the major diameter, and most throats are not round. Add to that the 0.001" step in your pin OD's and that a .4319" pin will not pass through a .4319" hole.

[flashhole]

I'm in Jepp's camp on this. Don't ignore the fact the bullets will obturate (expand) when fired making a better fit to the gun. You did everything right and came to the right conclusion. Good luck and let us know how you made out.