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Re: bullets: effects of differing diameters?

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03 June 2004, 02:11
knobmtn
Re: bullets: effects of differing diameters?


Deutschlander:

Almost all of my experience is with cast bullets so maybe I shouldn't comment on your jacketed bullet question but I think my experience is relevant. Also, since the years have caught up with my eyes a few years ago I haven't been shooting my 44's much. I put a scope on the one Smith but it just wasn't the same. Anyway, I forget some of the terminolgy so please bear with me. I actually slugged some 44 barrels. They aren't all quite the same. But those Smiths didn't vary too much. What I always did with cast bullets was to match up the bullet diameter with the holes in the front of the cylinder. I think those holes have a name but it eludes me at the moment. The different bullet diameters just give another variable to work with in determining an accurate load. In my experience getting the correct diameter bullet was a major contributor to accuracy. Just start on the low end with your powder and work up. With cast, at least, you won't get in trouble if you watch for pressure signs. Actually , even match grade rifle barrels can vary a bit in their bore and groove dimensions. Some makers even let you order them as a tight or a big bore.

knobmtn
03 June 2004, 02:20
<eldeguello>
Quote:

I mentioned in an earlier thread that I intend to buy some jacketed .44's for my magnum revolver. I'm getting ready to do so and am wondering why some are .429 and others are .430. Am I thinking correctly that the larger diameter would increase pressures and lower velocities at least slightly? Thanks again, fellas, for sharing your expertise.



NO! Not necessarily, that is. The controlling diameter you need to worry about is the chamber throat size through which the bullets must pass before they hit the rifling. IF your throat size is .429", (which isn't likely!!), it MIGHT cause a slight increase in pressures. But I'd be willing to bet that it is larger than .430"! In addition, you can't count on your barrel's groove to be right at .429" either. I suggest you mike your chamber throats, and use a bullet not more than .002" smaller. The less "swaging up" and "swaging down" that the bullet undergoes when it passes through the throat into the forcing cone and finally into the rifleing, the more accurate the round will be. You want to launch bullets in as undeformed a condition as possible. Revolvers are designed to be good bullet deformers!!
03 June 2004, 02:00
arkypete
I've no experience with 44 mag. 45 Colt and 44 special I've shot truck loads of cast bullets. What I've found is that the larger diameter bullet gives more consistant pressures, more uniform powder burn and more accurate.
See if you can get one bullet of each of the types you are interested in. Drop the bullet into the cyclinder, does it fall through? If the bullet does fall through that's not the bullet you want. This applies to cast and jacketed, both.
Jim
03 June 2004, 04:36
Deutschlander
Thanks, guys. I just measured the bullets I had been using, and they are .429(They're kind of cheap and therefore have a slight irregularity here and there, but that is the consistent measurement.). I tried, with moderate pressure, to force them forward through the chamber throats with a wood dowel, and could not(The throats are clean, BTW.). Apparently Smith makes them tight(This is a S&W 629). Does this mean I should avoid .430 bullets?
03 June 2004, 01:22
Deutschlander
I mentioned in an earlier thread that I intend to buy some jacketed .44's for my magnum revolver. I'm getting ready to do so and am wondering why some are .429 and others are .430. Am I thinking correctly that the larger diameter would increase pressures and lower velocities at least slightly? I'm assuming that all contemporary .44 barrels are the same diameter(correct or no?). If that is correct, why are bullets manufactured in differing diameters, and what are the effects?

Thanks again, fellas, for sharing your expertise.