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"HDCP" dram weight equivalent.

Discussion in 'Uncategorized Threads' started by cynergystan, Jun 25, 2007.

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  1. cynergystan

    cynergystan TS Member

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    What does the handicap (HDCP) designation on shotshells translate to in terms of dram equivalent? I apologize for my ignorance, but am new to this addiction.Thanks.
     
  2. slide action

    slide action Well-Known Member

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    The ATA dropped the Dram eqivalent a few years ago because it was confussing. The variable burn rate of powders was too much to contend with. Also many did not understand the term anyway. Most black powder would push 1-1/8 oz. of shot at around 1200 to 1290 fps. and 1 oz. of shot from around 1220 to 1325 fps, but even that was iffy. The ATA decided to go with a speed rating. 1-1/8 oz. max of 1290--1oz. max of 1325, --and 7/8 oz. max of 1350. My guess if a box has "Handicap" on it it will be pushing the upper range of that maximum. Personally I think we should go with the other target disiplines and simply limited weight and shot size. It sure seems to work for them!
     
  3. cynergystan

    cynergystan TS Member

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    1 and 1/8 ounce. Would that give rise to 3 1/4? Thanks.
     
  4. cynergystan

    cynergystan TS Member

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    I appreciate the information.Thank you.I shot 1 oz. 7 1/2, dram equiv. of 3, over the weekend. It may be my imagination, but I perceived a softer shot, less recoil and still managed to do just as poorly as I usually do.
     
  5. School Teacher

    School Teacher Well-Known Member

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    My understanding is that a "dram equivalent" is a measure of the equivalent amount of smokeless powder required to yield the same performance as a dram of black powder.

    A dram was a unit of measure of weight in the English (avoirdupois) system. A dram was equal to 1/16th of an ounce.

    Modern smokeless powders come in many varieties, densities and burn rates so it is not practical (and is dangerous) to convert old black powder charge weights to modern smokeless powder charge weights,

    As a basis of comparison, SAMMI (Small Arms and Ammunition Manufactures Institute) has adopted a table of shot weights and velocities for the more popular gauges and loadings that translate into “dram equivalent”. Some of these are as follows:


    12 Gauge:

    1 1/8 oz shot @ 1145 fps = 2 ¾ dram equivalent
    1 1/8 oz shot @ 1200 fps = 3 dram equivalent
    1 ¼ oz shot @ 1220 fps = 3 ¼ dram equivalent
    1 ¼ oz shot @ 1330 fps = 3 ¾ dram equivalent

    The “HDCP” loading may vary by manufacturer but my understanding is that it is the fastest ATA legal velocity for 1 1/8 oz of shot in a 12 gauge load. For Federal Cartridge, it is 1235 fps.

    Other terms you may see or hear for 12 gauge trap loads are:

    Ex-Lite or Lite Trap = 1 1/8oz @ 1100 to 1225 fps
    Light Trap = 1 1/8 oz 1145 fps
    Heavy Trap = 1 1/8 oz @ 1200 fps

    We still use other weights from the English system. One of these terms is the “grain”. A grain was the weight of one grain of wheat.

    One ounce = 437.5 grains.

    Another fine old unit of measure was the liquid dram which was equivalent to about one teaspoon. However, when applied to a liquid like scotch, rye or bourbon whiskey, a “dram” or “wee dram” was usually a shot glass full.

    I think I need to break off now to “drink some drams” of Rebel Yell, a fine Kentucky Bourbon not intended to be sold north of the Mason Dixon line.
     
  6. Michael Jobe

    Michael Jobe TS Member

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    Dram is a unit of measurement. 1 dram = 27.34 grains

    When a smokeless 1 1/8th oz. load is listed as 3 dram eq., that means it's the equvilant of 1 1/8th oz of shot over 3 drams (or 82 grains) of black powder. Well, since we haven't shot bp loads in years, that doesn't really mean much. They should just list it as 1200 fps rather than 3 dram eq.

    Rem, Win & Fed 1 1/8 oz handicap loads are rated at 1235 to 1250 fps. That puts them at, or close to being, a 3 1/4 dram eq. load.

    As for HDCP, that simply means handicap. It doesn't mean an actual dram equivilant. It's just the shell manufactures way of saying, "this is our handicap load, the heaviest ATA legal load you're getting from us". Again, this is stupid way of labeling shells, and they should list the actual velocity.

    Michael
     
  7. phirel

    phirel TS Member

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    school_teacher- Your post of dram equivalent numbers was correct but incomplete. SAMMI defines a 3 dram equivalent load as one having a 1 1/8 shot charge traveling at 1200 +- 90 feet per second. This means that the term 3 dram equivalent in a shell with 1 1/8 shot can actually overlap a 2 3/4 and 3 1/4 dram equivalent shell.

    Pat Ireland
     
  8. School Teacher

    School Teacher Well-Known Member

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    Michael:

    Not to be picky but, the English system was developed in the early 14th century by merchants and they did not work in decimals. One half of a whole was a half; one half of a half was a fourth and so on.

    In the English (or Customary) system, a dram was 1/16 of an ounce or 1/256th of a pound.

    To be accurate, 437.5 grains / 16 = 27.34375 grains.

    27.34 grains looks to me to be arrived at by rounding.


    Pat:

    Thank you very much for your information. I mostly shoot reloads and knowing that I have some leeway should one of my loads get questioned is comforting.

    Is there or what is the allowable variation in weight of the shot charge?
     
  9. BigM-Perazzi

    BigM-Perazzi Well-Known Member

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    for what its worth. I chrono'd some Rio paper 7 1/2 handicaps at 1265 out of my 34" tight bore Perazzi Mx-15. YMMV.

    Jim
     
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