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Can load data be used for any TYPE of bullet as long as it's the same weight?

Discussion in 'Ammunition & Reloading' started by zippygaloo, Apr 11, 2012.

  1. zippygaloo

    zippygaloo Oregon Member

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    I have some Hornady .224 55gr FMJ BT W/C bullets. I haven't seen any specific load data for this particular bullet. I do see load data for 55gr weight bullets but of a different TYPE (i.e. SP Spitzer, Etc.). Can load data be used for any TYPE of bullet as long as it's the same weight?
     
  2. mjbskwim

    mjbskwim Salmon,Idaho Well-Known Member

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    We'll get the experts soon,but I think you could use it as a starting place.Just the difference in the bullet co-efficiency would determine the FPS you want it at,hence the amount of powder.
    The Hornady book has it listed with all their other 55's,so you are probably right.
    What powder? I'll give you the grains
    Oh and go to Hornady for their ballistics tables

    OK I'm just spouting off,but I'll be burned down or said to be somewhat correct soon.LOL
     
  3. BK13

    BK13 PNW Member

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    Sorta... you would not want to use data for a conventional bullet for Barnes TSX or Nosler eTip. But for conventional lead-core jacketed bullet, data for other bullets should be a good starting point. If available, I always like to check the data from the bullet manufacturer though.
     
  4. Mark W.

    Mark W. Silverton, OR Bronze Supporter Bronze Supporter

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    The only time its a big worry is if the bullet is cast lead or coated lead and the data is for a jacketed bullet. As normally Cast or coated are restricted as to max fps allowed. And in can be quite a bit less then jacketed. There are also some very thin jacket varmit bullets which should use their own data to prevent jacket seperation due to moving to fast.
     
  5. deadshot2

    deadshot2 NW Quadrant WA State Well-Known Member

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    A powder load for a cartridge is dependent on lots of factors. Here are a few:

    Case internal volume
    Bullet Weight
    Amount bullet is inserted into case
    Bullet composition
    Temperature
    Primer Type
    Bore size vs bullet diameter

    Every one of these can affect the pressure that builds up in the firearm which is the first and foremost consideration for a safe load. If it wasn't then cases would be just stuffed with powder so we could send the bullet down range as fast as possible.

    Internal volume can be reduced if one is using a longer bullet, inserted to the same OAL as the data was developed for.

    Bullet composition, Lead only or jacketed lead, affects the amount of obturation when the bullet is hit with the pressure from the ignited charge. This can cause high pressures if a soft bullet meets a charge designed for a harder or jacketed bullet.

    Temperature can be a factor as well. Mismatch bullet and load, you may have a combination that goes overpressure with changes in ambient temp.

    Primer types are a component of the "charge".

    Bore sizes vary on firearms. Some do well with one bullet diameter and others do terrible with another. Even though bullets are advertised as a given diameter, some manufacturers vary. I have some bullets that all say .308 on the box but they mic @.307. No wonder my speeds are higher (less friction).

    It isn't absolutely necessary to use the exact same bullet for a given set of load data but it would be foolish to substitute and then just load your first rounds at the Max load.

    As with every new load, the phrase "Always start low and Work Up" is a "Prime Directive". Until one has more experience with various loads use the minimum 10% reduction and go up from there.

    Now to toss in another thought, the OP mentioned .224 FMJ BT W/C bullets. That usually means an AR-15. A big caution with these. AR's do not necessarily like the same loads as bolt action rifles in the same caliber. Check your powder Mfr's website for AR-15 loads. You'll break fewer cam pins that way.
     
    mjbskwim, Spitpatch, evltwn and 3 others like this.
  6. JackD

    JackD Elmira, OR Active Member

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    I use bullet weights as a starting point only. IMO a spitzer, boattail and round nose all have different length bearing surfaces and that means different levels of friction as it travels through the barrel. More friction means more pressure. At least that's how I see it.
     
  7. WolfTrap

    WolfTrap Inland Empire New Member

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    All depends on bearing surface. Pressure can go to Hade's if load data is used for one type of bullet design to another of different dimensions? Boat-tails loaded upped to max can be one big oops with an flat base bullet! Why one may ask? Bearing surface! However slight the length of surface can and will translate to high pressures beyond the firearms design.
     
  8. Spitpatch

    Spitpatch Forest Grove, Oregon Well-Known Member

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    Deadshot's list is comprehensive.

    The very most common error made by newer handloaders is when they stumble on (through reputation or otherwise), Nosler Ballistic Tip bullets (or Partitions), and switch bullets using a powder/primer charge that was near the top end, but absolutely safe with their previously favorite conventionally-contructed bullet.

    Deadshot's list comes into play for more than one item on it, and we can easily add JackD's and Wolftrap's "bearing surface" to that list (certain that Deadshot had it by implication).

    The Ballistic Tip is a long bullet for weight. (More bearing surface.) It also has a solid copper base (composition). It's length may change the amount of bullet necessary to insert in the case for proper operation in the firearm. Suddenly, our new experimenter is seeing pressure signs despite all else besides the bullet being equal (including bullet weight). Partition bullets have a solid copper web between the lead-core sections, which can also boost pressures. (Prior to modern metallurgy the original Partition bullets of a different alloy jacket actually had a "relief band" around the bullet at the section containing the web).

    Devotees of the Ballistic Tips and Partition bullets happily understand they need to reduce their top-end hunting loads just a bit to accommodate these fine bullets, and they also happily know they sacrifice nothing in velocity: the "reduced" load is of equal pressure as the old charge witht the old bullet, and therefore produces similar velocities.

    Utilizing a top-end load for a conventional bullet behind an "all-copper" or "green" bullet of the same weight could certainly magnify the stated concerns here. Users of these bullets most normally shoot a bullet of lighter weight than with a lead-core bullet, and so achieve similar bullet length and bearing surface (and comparable powder charge weights) by doing so.

    And, so, lest we (I) forget the question, the answer is, "Sometimes, but it's not a very good idea most of the time." (See Captain Deadshot Kirk's "Prime Directive").
     
  9. taylor

    taylor Willamette Valley Well-Known Member

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    I have an old Lee Loader in 38sp. it has a card with load data; any bullet 140-160grns use 1 scoop of 6 different powders listed. I've used it for years and got some pretty accurate loads with it.
     
  10. ma96782

    ma96782 Vancouver, WA Well-Known Member

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    You could be asking for trouble doing that but............

    Anyway, here is a WARNING that you should be aware of..........

    Did I ever do it?

    Yes, BUT...........I considered my alternatives, I also looked up data from several different sources and when I STARTED, I worked up my loads starting at the MINIMUM end of the scale. In other words......I didn't just start at the maximum end of the scale and expect it all to be safe.

    Being safe is important to me.

    Aloha, Mark
     
  11. AMProducts

    AMProducts Maple Valley, WA Jerk, Ammo Manufacturer Silver Supporter

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    If you want to break it down to a rule of thumb:

    Bullets of similar weight, and similar construction, of the same diameter are typically safe to use load data interchangeably. As was stated, as soon as you use a bullet of different construction, solid copper, solid brass, plastic tips, frangible or hollow points, the data may not be the same and it is best to use the manufacturers data.

    You should also take careful note of what primers were used, magnum primers can light a hot load of powder a lot faster than a normal primer will. It is exceedingly important to start low and work up, just picking a max load out of the book is a recipe for failure, either failure of accuracy, or possibly failure of your firearm.

    When developing commercial loads using one of the oddball bullets, we will use data from dramatically heavier bullets as we use the length of the bullet and the seating depth as a basis for how much powder we put in, and then reduce it by a factor. Typically the result is a very mild load, we will then adjust the charge until the velocity is closer to the specification we are going for, and then shoot it through a pressure barrel.

    One thing I'll tell you though, never load for max velocity unless you have an over-riding need to do so, what I look for when developing a commercial load is a very low standard deviation in muzzle velocity, as that almost always equates to all of the factors being balanced properly, and giving a very accurate, and often hard hitting load.
     
  12. WolfTrap

    WolfTrap Inland Empire New Member

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    OK..heres' the skinny on "Max Loads" and what nightmares are made of.
    30 years ago...John Gray and I were trading lies at the San Gabriel Rod n Gun Club when an ugly bird flew between us? Well, that bird was a chunk of Smith giving up the ghost! Most of you know what happened so I'll get to the man who loaded up the rounds. He used the max load without knowing what the dead bird could take? Nuff said.
     
  13. deadshot2

    deadshot2 NW Quadrant WA State Well-Known Member

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    That's usually the case with those who are shooting "their grandfather's Spanish American War sidearm" or such. Most correctly loaded cartridges, even if loaded to the max, are not the cause of failure in weapons that are either "pre-SAAMI" (1926), have excessive wear or round count, or have been modified.

    It's essential that one know their firearm even if not necessarily loading to the max for what ever reason.