How Bullet Coating Affects Performance

Discussion in 'Bullet Casting' started by argentwolf, Nov 8, 2019.

  1. For the past several years in watching all the excitement about coating cast bullets, I'm constantly taken back to the article from the 71st Edition of Gun Digest which speaks to performance of such formulations.
    I often wonder why a reloader hasn't added opinion to this conclusion with different calibers, loads, etc...I think it would be a great (different) read, and I'm kind of tiring of the different castings and colors, hoping for numbers.
    I'm seeing the hollow point coated cast bullets and wondering why, understanding the sense magic of jacketed pills and their use. Cast was always for me the cheap, in an attempt to match the serious carry's...jacketed performance.
    Am I alone and or might someone point me to a morsel of food for thought?
    Last edited: Nov 9, 2019
  2. Ten Man

    Ten Man G&G Evangelist

    There have been multiple posts, by G&G Members, about the various pluses and minuses of the different cast bullet coatings. Many of those posts are located in the GENERAL RELOADING portion of this Forum, in addition to the Cast and Coated portions of this Forum.

    You may want to try the SEARCH function, and narrow the parameters to the RELOADING FORUM.

  3. So you know of the article I referenced?
  4. Dutch

    Dutch G&G Evangelist

    I don't know the article you are referencing, but a forum member here sent me some powder a few years back and I started experimenting. At this point I powder coat most of my soft lead pistol bullets, some hard lead for rifle cartridges, and the pure lead Lee R.E.A.L. bullets for the muzzle loader.

    *Most* of my cast bullets are cast using Lyman molds, which drop bullets that are a few hundred thousandths over anyway, being designed to be uniformed up with a sizing die. So I have a wide selection of sizing dies to choose from and can size powder coated bullets back down to whatever diameter I choose (.452 to .454 for .45 ACP for instance) after they are coated. The coating bonds extraordinarily well and isn't damaged by sizing the bullet.

    I've noticed a general slight (almost negligible) increase in velocity, but have no way to accurately measure pressure changes.

    Most of these coated bullet cartridges I load to hard lead velocities, I don't approach jacked velocities with them. I seem to maintain accuracy that way, but don't get barrel leading.

    The powder coated black powder Lee R.E.A.L. bullets perform surprisingly well in an inline. I don't think it's a magic cure, but it does keep lead fouling in check.

    Anyway, ask away if you have any specific questions. I don't have many answers but can give you what I know.
    goat roper and Ten Man like this.
  5. Ten Man

    Ten Man G&G Evangelist

    I do not.
  6. runfiverun

    runfiverun G&G Evangelist

    woo hoo something I know and can write lucidly about.

    I didn't exactly see a specific question, but can throw out some generalities.

    they both have an effect on their central core only in different ways.
    the powder coat is more a protector and a follower.
    it goes where the lead goes and does what the lead does.

    they ALL can be manipulated to change the terminal effect for hunting or self defense.
    if they couldn't you wouldn't have varmint bullets, and big game hunting bullets, or dangerous game bullets either.
    [oddly the dangerous game solids steal most of their technology from large game cast bullet hunting]
    goat roper and Ten Man like this.
  7. While perusing the 'General Reloading' forum (whew!), the only opining noticed which came close to my interest was the mention of the book "Jacketed Performance with Cast Bullets" by Veral Smith (ASIN: B001BG2UM8), but its writing in 1984 I don't believe could speak too the newest coatings. I did send an email of inquiry to find out if their 4th edition might address such, but don't hold much hope.
  8. Huh, I will admit I'm a little perplexed we've not any in this forum who appreciate the articles of the Gun Digest publication and the incredible information its brought over the decades to the gun enthusiast. It's a priceless library I go back to time and time again...and as with my initial inquiry, the articles have set a very high water mark.
    Last edited: Nov 9, 2019
    Dutch likes this.
  9. Ten Man

    Ten Man G&G Evangelist

    It sounds as though you have the PERFECT OPPORTUNITY to be the "G&G Pioneer" in researching and sharing your findings on the topic of which you seek amplification. I'm sure there are G&G Members who would greatly appreciate the information, as well as hundreds of non-members, who read these forum posts, that could benefit from such publishing of the available information.

    As for the Gun Digest reference, I'm sure there are members that have appreciated that fine publication as often as you have, but have just not found this thread, or the inclination to comment on it. Since this is a new topic for the FORUM, it may take a while for it to catch interest, and/or REPLY activity. Don't be too hasty to assume there is no one on G&G familiar with Gun Digest as a resource for firearms enthusiasts.

    By all means, Carry On.
    TXplt and argentwolf like this.
  10. runfiverun

    runfiverun G&G Evangelist

    Veral's book has nothing on powder coating.
    it is about shooting cast bullets at high velocity.
    adding in a powder coat changes none of the real parameters or rules you need to follow to make that happen.
    nothing in the OLD gun anything addresses any of the dynamics of the two types of bullet fit a cast bullet needs to do it's best.
    some of Ed Harris's stuff on paper patching discusses some of the work arounds but not the why's or the what's that your trying to overcome.

    in fact I will go so far as to say anything that the OLD stuff does say to do to shoot lead fast is exactly the opposite of what you really need to do.
    they didn't study nor understand the way lead flows and moves under pressure.
    they took the same approach the car makers did to make their cars safer.
    that's kind of the right direction but they didn't combine the alloy with the rifles throat, bullet design, or take into account the powders pressure rise characteristics and ended in failure.
    to continue down that path they were forced to change the rifle and not their thinking.
    that is the OLD way of doing things.
    the new way is to re-work the design parameters and allow the alloy to move and flow under pressure but to contain the movement and adjust when/where the pressure is applied to accelerate the projectile.
    the designs that allow this stuff are NOT the OLD two diameter parallel designs [Lyman] they take everything into account including stuff like the angles the walls of the drive bands are cut, the length of the gas check shank, depth [and volume] of the lube grooves, angle of the slope on the nose and a convex front drive band to nose interchange.
    you also need to account for the COG and COR as well as any nose slumping that may occur [yes it happens to almost all of them and the good ones account for it]

    putting a powder coat on all of that needs to be taken into account also.
    there are at least 2 different types of powder.
    the amount added needs to be controlled so you ain't screwing up all of the above fitment issues, and the shell it provides will change some of the dynamic flow of the alloy under pressure.
    it also lowers the COF of the load [about 4-5%] and that definitely needs to be adjusted for.
    there are some benefits to the P/C that can be taken advantage of, but you gotta get the above right first and then your able to exploit them and move forward.
    I believe there are enough benefits to the coating that I have been slowly working on powder coating jacketed bullets to take advantage of them.

    none of that is in no gun digest book anywhere on the planet.
    Last edited: Nov 9, 2019
  11. BAM! Now you've come the closest to my even might be interested in reading the testing done for the article I referenced.

    "Six different types of .45 ACP 230-grain RN bullets were compared to see how they responded to the same load of gun powder. They were FMJ, plated, swaged, cast, moly coated and polymer-coated cast bullets...The bullets used in the testing were Remington FMJ, Berry's copper plated, Hornady swaged, Oregon Trail cast, Bear Creek Supply proprietary moly coasted cast and Bayou Bullets polymer coasted cast bullets...Four different charge weights of Winchester 231 were used. Ten rounds were loaded with each charge weight for a total of 240 rounds." more such details but I won't bore you...

    Now, maybe this sparks a flame of interest...and may further clarify my initial quandary.

    On another note that you may have an answer:
    While I'll admit to not being the sharpest knife in the drawer, what the hell's the purpose of the 'Concave Base' of cast pistol pills? I don't get it!
  12. runfiverun

    runfiverun G&G Evangelist

    concave base could serve several purposes.
    it could be there to serve as a place for a twisted tail on a paper patch to reside.
    it could be there to flair out and block the gas from escaping in low pressure situations.
    [think hollow base target type wad cutters]
    it could also be used to make the bullets work in a gun with poor diameters.
    many of them have over or undersized throat dimensions in relationship with the barrel.
    or the barrel itself could have a tight spot and you need to get through it then have the base pop out again.

    both of those situations need to be balanced with powder burn and duration, or can also be partially manipulated through seating depth.

    I have probably conducted that test myself at one point.
    I have the ability to make all of the bullets mentioned above [including the plated/moly coated ones if I choose to]
    what do you want to know?
    goat roper and argentwolf like this.
  13. I can see everything you reasoned for the concave base makes sense...I hadn't thought about trying to get a bad gun to shoot better, I've only rationed finding the best load for the gun at hand without clearly understanding what I might be physically trying to overcome. Thanks for the insight!
    FWIW, the article I reference earlier also tested 10 such bullets in .38 Super with some very interesting velocity results which I'm sure touch your want to test coating jacketed pills.
    As far as 'what I want to know'; it's simply results published of more such through testing of different combinations. I personally don't have the resources, time, nor knowledge to conduct such myself, but love a greater depth to the craft. I am tiring of the same ol, I shoot this bullet with this power just fine thanks. Speaks nothing to the amazing technology available today and a logical reason why one might choose something over the something else...smokeless powders are another deep dive which intrigues me to no end and I think many are missing out by simply choosing a 'popular' powder that everyone is shooting. The same with different cartridges...sorry, too many rabbit holes and not enough time. Also, I'm lazy and appreciate others chasing rabbits as long as they're willing to share their results. D'oh!
    So, share on Garth, share on Wayne!
    Mowgli T. likes this.
  14. runfiverun

    runfiverun G&G Evangelist

    ask away.
    we can go over pressure rises, burn times, gas volumes.
    why powders are fast or slow in different cases.
    you might be surprised why so many choose powder xxx in a certain case.

    the key is to just discuss specifics because question A can have different answers depending on the application.
  15. Curious, have you published or offered elsewhere any of your assessments or conclusions, and might you share where you acquired your applied knowledge?
  16. runfiverun

    runfiverun G&G Evangelist

    my stuff is easy enough to find.
    google my avatar name, you'll find my posts/testing/load data all over the internet, on reloading and shooting websites.

    all of it was gained from shooting, designing bullets, and testing stuff.
    I spent the better part of 3 years testing bullet lubes, and various components it's all in one 10-K post thread over at cast boolits.
    I also have data for the 300XCB wildcat round I designed over at the art and science of bullet casting.
    I go by fiver there and on the shotgun sites I frequent.

    as far as writing something to be published..
    there is so much stuff out there now, nothing I could put out would be ground breaking or probably even readable with my typing style.
    goat roper, Pilgrim Still and Ten Man like this.