How close is close enough

[flyer_55]

I have been reloading for a while now, pistol rounds for recreational shooting. I am using a Lee progressive turrent press and a GemPro 250 electronic scale, and a Redding 10X powder drop.

My question is how much variation in powder weight is acceptable without starting to blame the charge for my accuracy vs other factors. I had been using Titegroup with my 9mm, 38sp, and 45ACP rounds and given how hot that is, was always trying to throw a very accurate load. TG meters pretty well through the Redding, but occasionally I would toss 4.15 vs 4.2 and always wondered what that did to my trajectory. I don't have access to a chrono, so I can't do some 'workup/workdown' loads. I was hoping someone could give me a hint. In engineering, when a spec is given, it is usually accompanied with +\- tolerance values. I guess that is what I am looking for. I don't load anywhere near never exceed values.

This became a bit more interesting when I started throwing HRC 2400 for my magnum rounds. The weight and volume went up markedly per charge. Also I'm not sure the 2400 meters as consistently through the Redding drop. If you say don't sweat a .05gr delta, that's fine. I am just curious where the numbers start to change (is it a percentage of overall charge? linear or not?). Any advice on this? Appreciate wiser and experienced guidence.

[divingin]

.05 is not bad. I wouldn't even worry about it.

In any case, I don't think too many measures will throw any more accurately than that, and many scales won't even resolve that.

With pistol, you'll get a lot more variation from sighting and trigger release errors than you'll see from ammo variation, unless the latter gets really bad.

[tanks]

For a handgun, a tenth of a grain will not have any perceivable difference in POA.

[wbunning]

A lot of the answer here may well depend upon the kind of shooting you are doing. If you are shooting at 10-15 yards non-competetively, you are not likely to notice any difference with a charge delta of .05 grain, or even .10 grain. For one thing, most of our scales and balances aren't really that accurate, even though the Gempro claims .03 grain resolution. Other factors in your loading process such as uniformity and fit of the projectiles, seating depth, case prep, and crimp are just as likely to introduce as much or more variance.

If you are consistently throwing charges of TG that only vary by .05 gr, you are not going to do any better. Don't worry, be happy focus on keeping those other factors under control.

[tonyjr]

A lot depends on you / your gun and conditions .
I have 3 45s that could care less at indoor range [ 10-15 yards ]. when you get to 25 yards / meters - I load for each one .
Any pistol with a barrel shorter than 6 inches could care less at indoor range

[dreday383]

I was wondering kind of the same thing but more from a consistency perspective. I as well use specs well in limits but was wondering how accurate should we be throwing powder before we worry about tweaking with the powder drop? .05, .10, .15
.20 etc.


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[wbunning]

I was wondering kind of the same thing but more from a consistency perspective. I as well use specs well in limits but was wondering how accurate should we be throwing powder before we worry about tweaking with the powder drop? .05, .10, .15
.20 etc.


Sent from my iPhone using Tapatalk

[mjmagee67]

For USPSA shooting plus/minus .1 grain is just fine. I'm skeptical of any measurement smaller than .1 grain. Using my Dillon 1050 and one head stamp brass I've gotten SD's as low a 3. with mixed brass I regularly see SD's in the range of 8 to 13. That is damn good ammo and will shoot just fine.

[JackEllis]

For my rifle ammunition (I don't do handguns) I load to hunt and practice, the scale is good to around 0.1 grains. I measure each charge and use a single stage press. Acceptable error according to what I see on the scale is zero, knowing it could be as much as 0.2 grains, which translates to between 0.4 and 1% of charge weight, depending on caliber. If I can get SDs in the range of around 1% of muzzle velocity, and EDs around 1.5% of muzzle velocity, I'm good.

Another way to look at this is, do you want to spend all your time hand loading or do you want some time left over to shoot?