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Thread: at what velocity does leading occur?

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    Default at what velocity does leading occur?

    I'm thinking about hunting with my 45 colt (Ruger) and I like the idea of cast bullets for there ability to provide an "exit hole." I've been shooting 300 grain Hornady XTP MAGS over 23 grains of H110. This load makes my "Double Tap" factory loads at 1450ft/sec. with a 255 Keith seem quite mild. (That's their velocity spec. I've not chronographed them).

    Having done some reading. I've learned that the 260 gr. class of cast bullets will cleanly harvest Whitetails at around 900 ft/sec. and anything faster just flattens out the tradjectory a bit. True..?

    I am not interested in "scrubbing" lead out of my bore. I am however, interesten in knowing how much velocity I can get before "leading" becomes a problem. I see that "gas checks" help with preventing this occurance.

    So, in the event that I do begin to cast my own (without GC's), let's just address the "plain base cast bullets. How much H 110 can I burn before Leading becomes a problem..?

    Thanks fellows, Scott

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    Your question has been asked of me MANY times as i shoot cast bullets in many rifles as well as handguns. The reply is not as easy as it depends entirely on the bullet alloy as well as the lube. I shoot .44 mag bullets full bore in my 8 3/8'' Anaconda with zero problems and my 30-30 at 2100fps again with no problems at all. I do it by making the bullets super hard with Linotype mixed in the lead and an Alox and beeswax lube. With pure lead and crappy lube you would be lucky to not have any leading at any velocity. it all depends on the bullet and lube not as much as the velocity. I have seen .38's lead really bad at 700fps with crappy bullets.

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    There is a lot more to this than just how fast can I go. Most people are shooting plain base rifle bullets to 1800+ without leading cast from wheel weights. The most important factors are bullet size, cylinder throat size, and barrel grove size. If the bullet is smaller than throat size it will more than likely lead. If any of the throats are smaller than the groove size it will lead. Basically the bullet has to be the same size or bigger than the throats to seal so that gas will not scream past the base of the bullet removing lead and depositing it in the barrel. If you have any throats that are smaller than the groove size your bullet will be sized down and gas will bypass and remove lead to put in the barrel. So , if your bullet is big enough and the throats are big enough and the barrel is small enough and is not tapered bigger on the muzzel and is smooth enough and your barrel is not pinched smaller where it screws into the frame, it will shoot cast at 1500fps without leading. What this amounts to is the bullet must seal from the case to out the muzzle. If is doesn't then a lot harder bullet may not help and in fact may make it worse by not obturating ( wish I could spell) up to seal. If it doesn't seal it will lead. If it does seal it probably won't lead until velocity is very high.

  4. #4

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    Quote Originally Posted by 358wsm View Post
    I'm thinking about hunting with my 45 colt (Ruger) and I like the idea of cast bullets for there ability to provide an "exit hole." I've been shooting 300 grain Hornady XTP MAGS over 23 grains of H110. This load makes my "Double Tap" factory loads at 1450ft/sec. with a 255 Keith seem quite mild. (That's their velocity spec. I've not chronographed them).

    Having done some reading. I've learned that the 260 gr. class of cast bullets will cleanly harvest Whitetails at around 900 ft/sec. and anything faster just flattens out the tradjectory a bit. True..?

    I am not interested in "scrubbing" lead out of my bore. I am however, interesten in knowing how much velocity I can get before "leading" becomes a problem. I see that "gas checks" help with preventing this occurance.

    So, in the event that I do begin to cast my own (without GC's), let's just address the "plain base cast bullets. How much H 110 can I burn before Leading becomes a problem..?

    Thanks fellows, Scott
    If you use a bevel base bullet you will see a LOT more leading than with a flat base, to give a precise fps where leading occurs is about impossible with all the variables... Alloy used, powder, lube, bore constriction, It may not lead at all with a flat base bullet lubed with liquid Alox.
    1000fps-1200fps is PLENTY of velocity!

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    This is a question with many a many faceted answer. I agree with all these other post but there is still more.

    You question; .....................to cast my own (without GC's), let's just address the "plain base cast bullets. How much H 110 can I burn before Leading becomes a problem..?

    I have to ask. Why H110? The problem with than powder is that it really is only at its best with full power loads, and you probably don't want or need full power loads. A secret about good big bore revolver shooting with cast bullets is correct bullet size and bullet weight. Bullet size, because a good fit reduces leading and to keep velocity down just add bullet weight. I have a load for every big bore revolver caliber at about 950 fps. This is quieter (sub-sonic) and gives all the killing power I need except for those reach out yonder hunts.

    I really like the 280 grain weight range and H4227 is much more friendly than H110 for a powder. H4227 will load down to this velocity level with good ignition, H110/W296 will not. H4227 will leave some unburned powder but it's ignition characterisic will not change. It can also be used for full power loads but won't equal H110 for that purpose. 2400 and Unique will work well with moderate cast bullet loads also. Temperature of powder burn effects leading. With gas checks not so mush.

    Plain base bullets are easier and cheaper to cast and will work very well at noderate velocity and likey lots higher in the 45 Colt. It seems the larger the bore the less likely the loading. Slug the barrel and buy the sizer die about .001" larger. This also considers that the bullet fit through the throats of the cylinder, Basically we size to fit the cylinder throats and if they are too small we enlarge to all same size to allo a .001" over in the barrel. If you slug a barrel to .4517" (normally use .452" bullet) but the throats won't accept larger than .451" you would have to shoot .451" or recut the throats. They should be cut to .453" You can't shoot it if it won't go into the cylinder.


    Also bullet hardness is a factor. It takes a certain pressure to cause the bullet to bump up (obturate) in the bore for a tight fit. Hard bullets take more pressure. (BHN * 1430 = obturation) A BHN of about 16-18 or Lymans #2 alloy is great plain base to about 1100 more or less depending on all those factors of fit and lube and pressure. The 45 colt is the most forgiving caliber to cast bullets for and the most rewarding caliber because it just takes anything we throw at it. Heavy or light bullets, fast or slow. I've got a new Ruger coming and can't wait to get started with some loads.
    Is there nothing so sacred on this earth that you aren't willing to kill or die for?



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    Quote Originally Posted by Murphy View Post
    .... I've got a new Ruger coming and can't wait to get started with some loads.
    Great post Murphy. But, let's hear about the new Ruger. Perhaps in another thread? Would this be the blue 5.5" Bisley Blackhawk?

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    Default The bore is part of the equation, too.

    If you have a rough barrel, you can get lead deposits just scraped off the sides of the bullet in addition to that melted of the sides or the base.

    Good advice from the other postings. I used to buy (local caster) cast lead bullets when I lived in Arizona that had no leading at all. I moved and bought bullets from another source (a name brand) that leaded my barrel like I spread butter on toast.

    If you have lapped your barrel really, really smooth you can get a little more velocity and lower pressures with the same amount of powder as well as less leading.

    I don't have the scientific/engineering background or empirical data to make those statements from my own experience, however, but it makes sense, and I believe it.

    Lost Sheep

    Remember, only believe half of what you see and one quarter of what you hear. That goes double for what you get from the internet. Even this post.

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    Default that's what I call "gettin' an education"

    Thanks to everyone, I think I'm getting it. Looks like I'm going to need my cylinder bored, and my barrel slugged.., and I might as well throw in a "Bisley grip kit" too.
    Is it just rugers' 45 colt that has such variations, over sized cylinder chamber with undersized throats and then up to full size bore measurments, I mean, are the other Blackhawks (like the 41 and 44 Rem. mags) built like "Hour Glasses" also?

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    Default Caution!

    Quote Originally Posted by 358wsm View Post
    Subject Line: that's what I call "gettin' an education

    Thanks to everyone, I think I'm getting it. Looks like I'm going to need my cylinder bored, and my barrel slugged.., and I might as well throw in a "Bisley grip kit" too.
    Is it just rugers' 45 colt that has such variations, over sized cylinder chamber with undersized throats and then up to full size bore measurments, I mean, are the other Blackhawks (like the 41 and 44 Rem. mags) built like "Hour Glasses" also?
    As an institute of education, the internet has some unique and very strong recommendations for it, However, the peer review process is pretty haphazard. Anyone can post anything they want. If they post nonsense, or a typographical error, there it is. It may get corrected, or it may not.

    So, here's my caution to you; before you do anything, measure everything. If, indeed, your chambers are irregular, improperly sized, tilted or whatever, then you can decide to start machining (or replacing - if your cylinder is demonstrably out of spec, Ruger will replace it, but only if any gunsmithing work is clearly not responsible for the irregularities).

    To get back to your original question, "How much H 110 can I burn before Leading becomes a problem..?" Only your gun can tell you. Most of the discussion on this thread has been about figuring out WHY the leading happens (hot gasses melting the bullet base, for example, or blow-by softening the sides of the bullet). Load up some rounds and go.

    It will do no harm to measure your forcing cone and cylinder throats and to check the alignment and timing of your chambers. Slugging the bore will not only tell you the actual bore dimensions (and also tell you if the dimensions remain constant the entire length of the barrel), but I would measure EVERYTHING before doing ANYTHING.other than lapping the barrel and light polishing.

    If your measurements indicate some improvement might be had by reaming the throats or forcing cone, think about it, but "If it ain't broke, don't fix it." I would do nothing to it if it shoots OK.

    Gook Luck and Good Shooting

    Lost Sheep

    Remember, only believe half of what you see and one quarter of what you hear. That goes double for what you get from the internet. Even this post. Maybe especially this post.

    Do your own research when ANYONE gives you new facts on the web.

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    Default Some helpful threads

    I recalled reading some threads that spoke to the question of chamber throat/barrel dimensions relationships. Most of the posts were well-reasoned and seemed expert and valid (except for mine, of course). Happy research.

    http://www.rugerforum.com/phpBB/viewtopic.php?t=44348
    or paste this into your web browser if the link does not work
    rugerforum.com/phpBB/viewtopic.php?t=44348

    http://www.rugerforum.com/phpBB/viewtopic.php?t=26773
    rugerforum.com/phpBB/viewtopic.php?t=26773

    http://www.rugerforum.com/phpBB/viewtopic.php?t=44399
    rugerforum.com/phpBB/viewtopic.php?t=44399

    http://www.rugerforum.com/phpBB/viewtopic.php?t=44395
    rugerforum.com/phpBB/viewtopic.php?t=44395

    Lost Sheep.

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    There is no magic speed at which leading occurs as there are many, many factors that lead to leading. In some intances you can drive cast bullets 1500 fps from a revolver with no signifigant leading, in other instances you can push bullets 700 fps and completely gunk up the works.

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    Smile my two cents

    There was some really good meat and potatoes in the previous treads, just wanted to add that hardness is important and adding lino is probably the easiest, but you also can cook the cast and dump the them in water to harden them. It would be best to look the process in some reloading manual to be exact because it has been some time since I tried it, but I think that I cooked them for 30 minutes at 350 then dumped them in water immediately. Also you may want to research using moly as a lube, I used it in 500 smith stainless but only a short time. Moly will deteriorate stainless after so many degrees(and forget the number),but I think it is safe. Most important is if you like using cast and do lead your barrel just take 5 or 6 jacketed bullets with you to the range to shoot before you go home and they will clean her right up. Hope this helps

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    Quote Originally Posted by Snyd View Post
    Great post Murphy. But, let's hear about the new Ruger. Perhaps in another thread? Would this be the blue 5.5" Bisley Blackhawk?

    Naw, Perry. I have a 4 5/8" Bisley Vaquero, and is here now. I missed the rare Blackhawk Bisley 5 1/2", but bought a new 7 1/2" Bisley BH but didn't ship it to myself. It went to John Linebaugh to convert into one of his 500's. I'm still looking for a blued Blackhawk 45 Colt with a Bisley frame.
    Is there nothing so sacred on this earth that you aren't willing to kill or die for?



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    A little more about the heat treatment of cast bullets.

    Lead alloyed with tin will age soften over time as little as two weeks so keep this in mind if this is your alloy of choice, heat treating it will not help.

    Lead alloyed with antimony can be hardened by quenching if more than 4% is used added with a small amount of arsenic the bullet will also age harden over time. 7-14 days under 4% 2-3 days over 4%. Wheel weights will have a half percent of tin 3-4% antimony and quarter percent arsenic and will harden up to about 18 BHN and can be treated to get you all the way up to 30 BHN but thats not really needed unless your throwing out .454 around 65,000psi

    While it does seem harder is better bullets over 20 BHN are pretty much impossible to group over a hundred meters but this is not a concern for bear protection right! also to hard a bullet will lead your barrel just as easy as to soft.

    So wheel weights are pretty much perfect for casting bullets from well the clip on ones not the stick on's they are almost pure lead. So remember the higher the tin little to no response from heat treatment and the more antimony you use or is present in your lead the faster it will age harden and be able to be heat treated.

    Do you need a bullet that hard? Your just going to have to cast some and head to the range to find out.

    When you heat treat 425 degrees is the magic number test your hardness after quenching and then test again in 12 days straight wheel weights have quenched at 12 BHN and 12 days later have been a consistent 18-19 BHN so have patience.

    Rambling done Lee has a good book about bullet casting but most stuff in print is hard to absorb until you do it yourself and see the difference.

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