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brass/bullet weights

joshmb1982joshmb1982 Member Posts: 8,228 ✭✭
Ive heard one here a few times that some of you separate your brass and bullets by their individual weights. Assuming all brass and bullets are of the same brand, what is the point of this. I can understand measuring the length of the bullets for a more uniform COL but why weight?

What do you do differently when loading a 150gr fmj bullet in a 308 when this lot weights 149 grains and the other lot weighs 151 grains? Do you put in another 1/10th grain of powder because these bullets are a little heavier?

Also what do you do with the different brass weights? You cant add or subtract powder based on case weight can you?

Comments

  • jimbowbyjimbowby Member Posts: 3,496
    edited November -1
    [8D] heh Heh, I just weigh the .223 and .243 bullets to stay within 1/10gr-and keep them in groups of the same weight-

    The brass I don't weigh or measure the water cap. I just buy "match? cases-

    [:o)][:o)] JIMBO
  • bpostbpost Member Posts: 32,669 ✭✭✭✭
    edited November -1
    You weigh the individual components to obtain batch to batch consistency, sorting in groups based upon your tollerances. Consistency is helpful in accuracy. You adjust powder charges to fine tune for the best accuracy, you do not adjust powder charges based upon case to case variances in weight.

    If you are loading for match type accuracy there are many steps involved in finding it.

    If you are loading "blaster" ammo, it is a waste of time. Pick a charge for reliable function, acceptable accuracy and go for it.
  • perry shooterperry shooter Member Posts: 17,105 ✭✭✭
    edited November -1
    Hello joshmb 1982 I may be reading something in your post that can get you in BIG trouble. . From a logic point it would seem that one would need more powder to push a heavier bullet HOWEVER THIS is THE OPPOSITE of what you EVER want to do . The heavier bullet will cause more pressure with the same power charge and You may Blow the rifle or pistol . It sounds like you are fairly new to reloading WELCOME and please continue to ask questions but NEVER try to second guess powder charges for different bullets GO BY THE BOOK No Book= = =No LOAD
  • dcs shootersdcs shooters Member Posts: 10,870 ✭✭✭
    edited November -1
    quote:Originally posted by joshmb1982
    Ive heard one here a few times that some of you separate your brass and bullets by their individual weights. Assuming all brass and bullets are of the same brand, what is the point of this. I can understand measuring the length of the bullets for a more uniform COL but why weight?

    What do you do differently when loading a 150gr fmj bullet in a 308 when this lot weights 149 grains and the other lot weighs 151 grains? Do you put in another 1/10th grain of powder because these bullets are a little heavier?

    1/10th of a grain is NOT going to make a difference in bullet weight. DO NOT change powder charge for them. You are just asking for trouble if you do.

    Also what do you do with the different brass weights? You cant add or subtract powder based on case weight can you?


    Another case for leaving the powder charge the same.

    Why would anyone go to all the trouble of changing a powder measure and scale a 1/10th of a grain for a grain difference in weight of a bullet or piece of brass is way beyond my way of thinking.
  • jonkjonk Member Posts: 10,121
    edited November -1
    For 100 yards or less for an average factory gun and average components, I wouldn't bother.

    I have done this on occasion though. For my Savage 12 .223 I saw a group size reduction at 300 yards from 1.5" to .9".

    I also have done this with milsurp components. I got a batch of surplus 147gr .308" bullets that had an extreme spread of 141 to 150 gr. That's pretty big. They aren't great bullets to start with but by sorting them I got my group size at 200 yards with my M1 from 8" to 6". Mind you the 8" reflect the occasional flyer but those were largely eliminated by sorting.

    See, point of impact will change. A heavier bullet will usually strike lower for the same powder charge, and vice versa. You eliminate this spread by sorting.
  • zimmdenzimmden Member Posts: 237 ✭✭
    edited November -1
    Separating brass by weight is done by most benchrest shooters who want to eliminate the most variables in the accuracy game. Brass that weighs the same (say .5 gr or less difference)will have the same intrenal dimensions ie; brass thickness and case capacity. This results in more consistent bullet neck tension and more consistent powder burn(pressure). Benchresters select, match and use only 20 to 50 of the most evenly matched cases. This is just one of the many small things that these shooters do to achieve sub 1/4 MOA accuracy. It is not necessary for the shooter satisfied with 1 MOA. No powder variations are used with brass of different weights. This brass is used in separate lots for testing, practice etc.
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