Twist Rate

topic posted Sun, May 25, 2008 - 9:37 PM by  Unsubscribed
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How do you figure out what the ideal bullet weight is for a given rate of twist in a given caliber?

For example, I have a .357 lever that's a 1:30 twist. Far as I know, that's a pretty lazy twist for big bullets, much better for lighter ones...but what's the ideal size? how do I figure it out, aside from trial-and-error? what's the formula?
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  • Re: Twist Rate

    Sun, May 25, 2008 - 9:41 PM
    most say a 1/18 is optimum I dunno though I have a 1/20 on a 22 hornet ad it is a fast little bugger and accurtate
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      Re: Twist Rate

      Sun, May 25, 2008 - 9:45 PM
      Well I hear it depends on how much lead you're throwing down the barrel too. Tighter, faster twist is good for bigger bullets... Longer twist is better for lighter bullets. And I'm sure slower/faster has a lot to do with it as well. And probably how much bullet sidewall is contacting the bore, and the diameter of the bore... a 158 grain bullet has very different characteristics and shape, sized for a .22 barrel or a .40 barrel

      At least, that's what I seem to gather.

      I'm hoping someone knows how to figure it out, or what's the best config. for my particular needs at least. We'll see I guess.
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    Re: Twist Rate

    Sun, May 25, 2008 - 9:50 PM
    look on the website of the company that made the gun. You might find out what grain bullet to use with the twist. The right grain with the twist is real important for accuracy.
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    Re: Twist Rate

    Sun, May 25, 2008 - 10:47 PM
    www.stevespages.com/page8e.htm

    These charts only go up to 1:25 for .357 are you sure of that rate?
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      Re: Twist Rate

      Sun, May 25, 2008 - 10:51 PM
      yea... well at least the pamphlet that came with the gun from Rossi says 1:30 twist... it says it individually for each caliber... I guess they just really like 1:30 twist rates?

      I probably oughta verify with a cleaning rod with a tight patch, and a ruler just to make sure something isn't lost in translation. They are a brazillian company, after all, and although I have no experience with brazillian brochures or product booklets, I've read some pretty screwy ones from china and whatnot.
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        Re: Twist Rate

        Sun, May 25, 2008 - 11:01 PM
        Maybe 1 in 30cm, which would be about 1 in 12" that would come out about right, no? Do they list the barrel length in inches or cm?
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          Re: Twist Rate

          Sun, May 25, 2008 - 11:05 PM
          They list barrel length in inches... but you still might be right about the metric twist-rate. It's one thing to measure exterior dimensions for marketing, it's another thing to measure your interior tollerances for machining. I wouldn't be surprised if all the innards are metric. I'll check it out in the morning when I have enough brain power to count inches and revolutions.
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            Re: Twist Rate

            Sun, May 25, 2008 - 11:22 PM
            I'll bet your thinking about counting inches in the bedroom. lol Let us know what the twist rate is in the morning. HA HAH AH A HA AH AH AHA HA

            Sorry, couldnt resist the kinda crude comment. It just struck me funny.
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              Re: Twist Rate

              Sun, May 25, 2008 - 11:24 PM
              I just sprayed tea out of my nose.
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                Re: Twist Rate

                Mon, May 26, 2008 - 2:55 PM
                Yea those inches seem to be doing alright, fortunately no twist rate, we try not to get *that* wild.

                I guess while I've got the ruler out I might as well check the gun bore, eh?
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      Re: Twist Rate

      Sun, May 25, 2008 - 10:52 PM
      You can try the old cleaning rod down the bore trick to figure the twist. Ya know, just measure how many inches it takes to give the rod a complete turn.
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        Re: Twist Rate

        Sun, May 25, 2008 - 10:54 PM
        guess your post came in right before mine. lol those brazillian's might have a different way of measurement. I'd try the cleaning rod deal.
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          Re: Twist Rate

          Sun, May 25, 2008 - 11:06 PM
          haha too slow! Useless comment, brent, USELESS!!!

          Oh that's gotta hurt!
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    Re: Twist Rate

    Mon, May 26, 2008 - 2:53 PM
    Okay okay...

    I checked the twist rate with a rod and patch, it really is 1:30.... whoa I've never even heard of such a long twist in this caliber.

    Rossi is mum on the subject of ideal bullet weight.

    Any more ideas? I'm gathering data so that I'll be sure to get an ideal bullet mould for casting.
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      Re: Twist Rate

      Mon, May 26, 2008 - 2:57 PM
      Marlin does a 1:16 in their '94 .357
      • Re: Twist Rate

        Mon, May 26, 2008 - 9:31 PM
        1 in 30 does sound a bit weak.

        Ideally you choose the bullet on what you need it to do. If you want to hunt deer then look to a jacketed 158 grain. If you want something to plink then a lead or mollycoat round would be ok. If you want something that will get you optimum knock down against humans in both the carbine and pistol then go with a 124 grain JHP or JSP.

        Once you choose the bullet, then you work up a powder load. This is where it can get tricky. Which powder? Some people like the cleanness of Accurate powders, others like the versatility of Hercules or the Dot powders. Red Dot, green dot, and their kin can be used for everythings from pistold to shotguns to small rifles. Accurate #5 is clean but leaks from some powder throwers. Norma is the fastest burning, Hercules fills the case better...

        Once you settle on bullet and powder, you work up the load that works best for your particular rifle. Every gun is different.
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          Re: Twist Rate

          Mon, May 26, 2008 - 10:42 PM
          I was hoping to build some 180 grain setups but I really don't think that's gonna happen with a gun that's basically a rifled smoothbore... rifled straightbore? You know what, it takes too much explanation to be funny anymore. I started out trying to be clever though.

          I really want to cast my own lead. There's gotta be a way out there to make your own gas checks for your own cast bullets. Jacketed bullets are alright, and one day when I'm a more refined human being I'm sure I will enjoy the precision and enhanced effectiveness of factory jacketed bullets. But for right now, I'd be plenty happy with a hard-cast something or other, that costs little or nothing to make out of wheel weights and tin cans, for shooting wheels and tin cans, and it would be an added bonus if said bullet could perform decently on a deer. I'm just trying to figure out what to get, and I figured bullet weight is a good place to start, since it has a lot to do with how well it would work in a given gun with a given twist rate.

          Any suggestions in cast-bullets?
          • Re: Twist Rate

            Tue, May 27, 2008 - 12:59 PM
            That's cool that you want to make your own cartridges EOW style. I'd get some factory components, get used to it, then when you start making your own gas checks and bullets you will have the experience to see what will work and what won't. The gas checks shouldn;t be terribly hard to make...punch out round copper disks, then flange the edge to your caliber.

            Anyhow, here are two of my favorite reloading sources. You can buy moulds, and a 2nd device that resized & lubes the cast bullet, and lastly gas checks. Both are really great companies and you'll drool over their catalogs.


            www.midwayusa.com/
            www.natchezss.com/

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