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Effect of powder weight variance of 0.1 -0.2 gr.

ArbyArby Member Posts: 668
Most digital dispensers tout accuracy (+/-) 0.1 gr. , depending on the powder being used (ball vs flake) that is generally what you get...especially using ball powder...in my experience anyway.

My PACT Dispenser which worked perfectly for 15+ years finally bit the dust so I am back to using my RCBS powder throw which I used many years before the PACT. The up side of manual throw is it is much faster and I get very accurate weights with an occasional variance of (+/-) 0.1 -0.2 gr... I only load 45acp, 45LC, .357mag , .38spcl and always load factory specs and am currently using HS-6 and H-110 where appropriate. My experience has been very little if any difference between factory ammo and what I reload.

My question is where do you draw the line with regard to powder charge variances ...are you okay with (+/-) 0.2g , 0.3g , etc.?

This why I never get close to the redline charges noted in the manuals since I don't know what effect a small variance of powder weight would be on the top end.

Comments

  • Hawk CarseHawk Carse Member Posts: 4,381 ✭✭✭
    edited November -1
    I do not worry about a little variation in measured powder charges for ordinary pistol ammo. +/- 0.1 gr is nothing, and 0.2 not bad.
    I put up with 0.3 with large flake 700X for a good while until I put a vibrator on the hopper to settle the powder into the cavity.
  • nononsensenononsense Member Posts: 10,928 ✭✭✭✭
    edited November -1
    Arby,

    I draw the line as close to zero as possible. We now have powder measures and scales which will measure/weight to 1 grain of powder. That's 1 piece of the powder or a granule. So being precise is generally acceptable if necessary.

    The 'rule of thumb', if there is such a thing, is that as the powder volume gets smaller, the error also needs to get smaller. In essence, if you have a small volume case, you need to be more precise in your measurement since your error is now larger by comparison to the volume. Conversely, if you have a huge case, then the amount of error increases. This generally holds true with rifle cases, which can be checked by shooting over a chronograph. However, the caveat here is that the cases themselves can show substantial differences in capacity which will affect the powder load as well. A .308 Win. case with thicker walls will hold less powder than a case with thinner walls. So we weigh the cases and segregate them for accuracy.

    Best.
  • yonsonyonson Member Posts: 940 ✭✭✭
    edited November -1
    The greater the amount of grains in the load, the less the percentage of variation. I reload 25 ACP, which takes just over 1 grain of powder. Plus or minus 0.2 gr. is approaching 40% variation in the load, which I think is excessive.
  • perry shooterperry shooter Member Posts: 17,105 ✭✭✭
    edited November -1
    I agree in a small case a small Variance IS NEEDED I have loaded and shot over 200,000rounds of match grade 45ACPover the last 40
    years IN MY OPINION
    THE STAR RELOADING MACHINE HAS THE BEST POWDER DROP SYSTEM OF ANY it is less That .5 ten's of a grain with Bulls-eye I did tons of ransom rest testing
  • charliemeyer007charliemeyer007 Member Posts: 6,572 ✭✭✭
    edited November -1
    I drop 20 charges in the powder measure before/after any adjustments. Once set I weigh every 10th one as a check. I keep the hopper at least 1/2 full. It is on a different bench than my press. Scales are 0.1+/- grain of actual. Some powders meter much better than others.

    If I'm really trying, I drop light into the scale pan and trickle to the weight. Some people weigh the primer, case, bullet and sort accordingly.

    Back in the day I shot many thousands of rounds of 06 and 308 and never weighed a charge - just a full case of like H-4831.
  • gunnut505gunnut505 Member Posts: 10,290
    edited November -1
    The old volume vs. weight thing again.
    Lee ships little dippers in their die boxes (say that 5 times real fast) that hold a set volume of certain powders, does that mean they value volumetric measurements over weight?
    No.
    Same applies to the interchangeable rotors in the Lee powder measures; a certain volume at a certain load density gives an approximation of a charge weight.
    In my 550b, the powder measure is infinitely adjustable by volume to drop a charge of the desired weight, but I still run 10 drops to average the given charge weight.
    A tenth of a grain is acceptable, high or low, in the calibers you load, as long as you chronograph & check for signs of high pressure.
    Changing the specified components without working up from 10% below the listed load can be dangerous, but some folks don't know or care, as long as the bullets go bang.

    Some shooters try to gain every advantage possible, by weighing every case, charge & projectile to ensure uniformity. Consistency is the key to accuracy, especially past 500 yds.
  • ArbyArby Member Posts: 668
    edited November -1
    From my original post.

    My PACT Dispenser which worked perfectly for 15+ years finally bit the dust

    Well not quite yet...I just hate it when I do something stupid like putting the cart before the horse. As many times as I have use my Digital Dispenser and scale for some reason I tried to set it up bass ackwards. I tared the scale before getting the scale to talk to the dispenser...DUH!

    When in doubt get out the operators manual and just follow the bouncing ball...once you follow instructions it works just fine...exact weight every time.
  • best defensebest defense Member Posts: 30 ✭✭
    edited November -1
    For 45 ACP cases you should be just fine.

    quote:Originally posted by Arby
    Most digital dispensers tout accuracy (+/-) 0.1 gr. , depending on the powder being used (ball vs flake) that is generally what you get...especially using ball powder...in my experience anyway.

    My PACT Dispenser which worked perfectly for 15+ years finally bit the dust so I am back to using my RCBS powder throw which I used many years before the PACT. The up side of manual throw is it is much faster and I get very accurate weights with an occasional variance of (+/-) 0.1 -0.2 gr... I only load 45acp, 45LC, .357mag , .38spcl and always load factory specs and am currently using HS-6 and H-110 where appropriate. My experience has been very little if any difference between factory ammo and what I reload.

    My question is where do you draw the line with regard to powder charge variances ...are you okay with (+/-) 0.2g , 0.3g , etc.?

    This why I never get close to the redline charges noted in the manuals since I don't know what effect a small variance of powder weight would be on the top end.
  • MobuckMobuck Member Posts: 14,081 ✭✭✭✭
    edited November -1
    I don't tolerate much variance in my powder charges. 0.1 grain MAY be acceptable for charges 25 grains and above but I'd be concerned with 0.2 variance in small handgun cases. If you're meaning 0.2 from the target weight, that's 0.4 between high and low which is totally unacceptable if the charge weight is 5-6 grains.
  • bpostbpost Member Posts: 32,669 ✭✭✭✭
    edited November -1
    Two tenths with pistol type loads and shotguns using fast powder is BAD!

    Two tenths with RE25 or 4831 in a rifle case holding above 50 grains of powder, not so much unless you are on the ragged edge of pressures to begin with.
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