Powder tolerance. How tight are you

Striker33

Striker33

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Hey guys,

I am relatively (last 2 years) new to reloading, and was curious about how tight you are with your powder measurements. I started using a cheap lymann scale... which I hated as I figured I could be aout as much as .2 gn, so I bought a digital jewelers scale that measures to the 1/100th's of a gn. I noticed slight variations in weight when I measure the same load multiple times ( 2-4 1/100th gn) is this typical? I don't think it is anything to worry about, but I am curious how tight people go. When I pour, if I am out 2/100ths I don't worry... When do people dump and remeasure overages?

I am loading a 308 hunting round with 44.5gn IMR 4895 shooting sierra 150gn pro hunter bullets. I also noticed that my OAL varied from 2.765-2.785 with a target of 2.775. Is this also normal? I thought it was related to depression of some of the lead tips, but I am not sure.
 
If you're within HUNDREDTHS of a grain, you're better than 99% of reloaders out there.

With my 550B and a good flowing ball powder, I'm within .1 grains 19/20 times (about). I'm not loading for 'match' accuracy most of the time, so .1gr difference is usually 'good enough' for me.

Also - differences in OAL is not uncommon in my opinion... the ogive on the bullets is not always EXACTLY the same (especially on 'hunting' bullets), and since that's usually where the seating dies contact the bullet (I believe), it's difficult to get 100% consistency. I wouldn't give two hoots about 2 hundredths difference of OAL, but that's just me. As long as it fits in the mag, I'm good. ;)
 
When I was a kid my dad used to tell me stories about guys that would measure using tweezers... so I was curious... These are hunting rounds, I am not shooting over 250 yards. The fact is even on my best day 1moa at 100 yards is good for me. I think the rounds surpass my capability.
 
I loaded using mixed brass, and thrown charges.
At 100-200 yards I couldn't tell the difference between those and the loads I use all same headstamp/measured charges.
For my target/match loads I would still use same headstamp brass and weigh all charges, I paid for the rifle I might aswell use the best ammo I can put together.
 
When do I dump and remeasure?
When it's past 0.2grs.

To be honest, I don't even check weigh on my bulk pistol ammo (9mm). Using a Lee auto disc it dumps within +/-.1gr and that's good enough.
I'll trickle for rifle rounds. That's easy enough to hit bang on. Using the thrower, I'll check every 5 rounds. If they're within 0.2, its good.
Mind you, I'm not running pressures at the bitter edge of disaster nor loading for benchrest. YMMV.

(E) :cool:
 
In all practical purposes a quarter of a grain ( 0.25gr) is the tightest measurement I choose to go. Sometimes its a toss up of 3 groups 0.5gr difference of which one is better.
 
This depends on what I am reloading for and how hot the round is. If you at or close to max then I would not want to be .2gr over, if you plan on shooting for groups (less then MOA) then I like to be more precise. I use a beam scale because they are with out a doubt more precise.
 
I also use a Lyman beam scale but I am within +- 2 sticks of powder on every round. Mine is very repeatable, always shows the same weight no matter how many times I take the pan off and put it back on.

As for the varying over all length it is very normal and is due to not only the lead tips being slightly different and the ogive may be a little different as well.
 
.2 has been my threshold for the last 40 yrs.

Just as an aside, when I was just starting to reload, my dad and I pulled the bullets on some factory loads ( you have to remember this was before computerized metering that is used now) and found as much as 5 full grains of powder difference in shells from the same box.
 
Right down to the granule, if an extra trickles out I'll leave it, if 2 fall, I'll pull 1 or 2 out.
And people wonder why I don't let them shoot my ammo....
 
I won't dump a charge if it doesn't read exactly the same as the last one. I believe the accuracy of my scale/dispenser is +/- 0.1gr, so theoretically that's +/- 2/10ths of a grain between rounds.
 
I've started using ball powders and use what the thrower throws, my "precision rifle" ammo is trickled up on a beam scale and I use the thinckness of the needle/bar on the scale, anything more gets put back in the thrower and try again.
 



These groups were shot with 0.5 grain variation from 1 (38.0 grains) to 8 (41.5 grains) at 200 metres.

Five lots of Winchester, using one box of each lot, were dismantled and the powder charges weighed. One box had a 2.1 grain variation, and over the 5 lots, the variation was 3.5 grains.

Most hunting rifles would not see any huge difference in accuracy.
 
It all depends on the game you play or the game you are after. If I was loading for pistol, service rifle or a hunting round a thrown charge that is +/-.3 gr would be good enough. For my long range stuff, bang on the exact weigth. With my scale that will read .02 gr. I don't need a scale that will read .001 or .002 thousands of a grain because I refuse to cut kernals of powder.
 
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