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Old March 4, 2011, 05:33 PM   #1
twins
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Weighing bullets..anyone?

Normally, I do not sort/weigh bullets before reloading. But this time I decided to see the variance between the weight of the bullets in the same package. I was sorting through a package of 100 Prvi 55 gr SP bullets (.224) for a p-dog load and found the lightest weighed 54.1 gr and the heaviest was 55.7 gr. The majority (about 2/3) of the bullet came in at 54.6/54.7. Only 16 came in at 54.9/55.0.

Is this about normal?

Anything to be concerned about if the weight is within +/- 1 grain?

Thanks.
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Old March 4, 2011, 05:55 PM   #2
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We guys who use cast bullets routinely weigh bullets for top accuracy. I'll take a batch of bullets and sort them by one standard deviation. A batch of bullets normally approximates the standard distribution that you learned about in statistics class. There's a good article explaining the process under this link.

Several years ago I bought a batch of blemished HPBT bullets and I've also sorted them by weight. I was astonished to get almost three grains between the lightest and heaviest bullets, so I put like weights in small zipper bags and load them in batches with like weights.

Weighing bullets is not unheard of.
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Old March 4, 2011, 09:13 PM   #3
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I weigh bullets occasionally, but it's normally just out of curiosity. I don't change my loading practices, based on the results of the weigh.

Most 'average' bullets from 50-100 gr seem to vary 0.3-0.5 grains (some a bit more).

The heavier the bullet, the larger the variation by weight, but the smaller the deviation by percentage.

Premium bullets..... They're a different story. Barnes, Swift, and Woodleigh have supremely impressed me with their consistency. (Often no more than 0.1-0.2 gr variation, even at 180+ grains).
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Old March 4, 2011, 10:06 PM   #4
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I sort by weight and load in batches as well, but its not weight but concientricty (I KNOW I spelled that wrong!!). Or how even the jacket is. If its thicker on one side than the other then the bullet will wobble throughout its rotation. This plays a bigger impact than the slight deviance in weight. Though you may have a difference in fps over a crono (no more than +- 5 fps, I'd imagine) due to different weights if they're extreme. IE 2-3 grains.
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Old March 4, 2011, 11:40 PM   #5
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consistent bullet weight = accuracy

A number of years ago I read an article, Guns and Ammo I think, were the author weighed 22 long rifle bullets. He found: 1. Considerable variations in bullet weights. 2. The greater the deviation in weight the greater the spread in the pattern. 3. He used those within .1 grain of each other for his matchs. 4. His match scores improved dramatically.

Based on that article, I weigh my bullets, group them and develop loads for each group.
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Old March 5, 2011, 12:38 AM   #6
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I generally only weigh and separate what I use for long range shooting--.2gr variance doesn't mean much for a couple hundred yards on a whistle-pig. It means a hellofa lot at 1000 meters. If I'm loading 90gr. FMJ/BT in 6mm, every one in the batch is exactly 90gr. They stay on the plate that way.

I also weighed and separated a bunch of mil-surp fmj's for my mosin. I found out of the 1000-round batch the lightest was 143gr. while the heaviest was 151gr. They were supposed to be 147gr. Most were within 1gr. But having load batches matched by weight within .5gr has really tightened up groups even on the old Russian M91.
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Old March 5, 2011, 04:05 AM   #7
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Weighing cartridges is next to useless. Weigh your brass next time and see what the differences are. You could have exactly the same cartridge weights and completely different powder and bullet weights from shot to shot. That'd be like weighing two cars and guessing they'd go the same 1/4 without looking under the hood first. That chevette with a v8 and nitrious might beat that yugo with a fat guy driving it and a weight set crammed next to him.
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Old March 5, 2011, 09:10 AM   #8
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Quote:
Originally Posted by semi_problomatic
Weigh your brass next time and see what the differences are.
Heh! This stuff will drive you crazy. I know guys who weigh primers, brass, bullets, everything trying to be absolutely consistent.

You're right that brass is another variable in our reloading hobby and if you're searching for that magical, consistent load then looking toward each component is the way to go. I have marked molds so that I could match the orientation of the mold with the orientation of the brass for max accuracy in BPCR shooting. Then you get into chamber orientation, where the indexed cartridge is loaded into the chamber the same way each time. This stuff will drive you buggy.

Quote:
Originally Posted by FrankenMauser
Premium bullets..... They're a different story. Barnes, Swift, and Woodleigh have supremely impressed me with their consistency.
That's my experience too. I weighed a bunch of Nosler Ballistic-tips one day, and after a sample of ten, had a SD of -0-. SO, being the perverse guy I am, I weighed the whole box of 50. All bullets within 0.1 grain, SD = 0. I was truly impressed.
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Old March 5, 2011, 12:18 PM   #9
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Funny thing that you would post...

...asking the question, because it was one I was checking last night on some "124" grain 9mm plated bullets. Weighted a sample of ten bullets and got the following:
Average weight: 123.93 grains
Minimum weight: 123.6 grains, deviation from average -0.33 grains (0.267 percent lower than average)
Maximum weight: 124.2 grains, deviation from average 0.27 grains (0.218 percent higher than average)
Standard deviation: 0.189 grains (0.152 percent)
Standard deviation range of 123.74 to 124.12 grains with two bullets below the range and two above.

Given the above calculations and a 25 yard range, I suspect I have little to worry about other than my own pistol shooting ability or lack thereof.
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Old March 5, 2011, 12:37 PM   #10
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Oh yeah and

Pawpaw that weighting 50 bullets is impressive.

(In my couseling training we had another name for it, oc.. something or the other - but it's something I'd easily see myself doing if I had one of those high dollar plug in scales instead of a RCBS 505 beamer.)

I'll remember the brand when I get into rifle reloading.
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Old May 30, 2017, 08:37 AM   #11
Mad_Max
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Weighing Bullets

I've never tested any bullets that I've weighed out, but years ago out of curiosity I weighed my arrows for my compound bow and had 2 arrows that weighed exactly the same to the tenth of a grain and marked them and when I shot my arrows at a target the 2 that weighed exactly the same every time tried to hit in the same spot and were touching each other. So it seems to me that weighing bullets out isn't a waste of time if you want better groups and consistency in your reloads.
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Old May 30, 2017, 09:09 AM   #12
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For target shooting weighing and sorting will get you an added layer of accuracy I would think. You would see more effect in a 34 grain .20 caliber being off by .1 grains than a 180 - 190 grain being off by .1 grains.

I weigh and sort and what I have found is that most mass produced bullets have good quality control with even the bulk rifle bullets being within .2 grains max over or under weight and more expensive SMK's and Bergers being for the most part within .1 or dead on box weight. However I think it is worth taking the time to sort in long range and benchrest where .1 MOA can make or break a score
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Old May 30, 2017, 09:52 AM   #13
Don Fischer
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I weighted them a long long time ago. First were a box of 7mm Herter bullet. Scary to think there could be that much difference is the same box of bullet's. Got me crazy and if they are that far off, I really need to weight them all. I weighted a box SMK
s after that. Can't believe how boring it is to sit through a whole box of bullet's and every one weigh's the same. So my go to bullet back then and still today was Hornady so I weight'ed them. Last time I did them. There were small difference but not much. I use Hornady V-Maxs in one 243 and SMK's in the other. I got going on the V-Max bullet's because they do shoot well and old habit, love them Hornady's. Generally most of my varmint bullet's are SMK's.

I have tried very few different bullet's over the years but have used Speer Hot Core's in a 7mm mag. the rifle loved to stuff and they really hold together great. I don't know about Hot Core's today but if they made a 130gr Hot Core in 6.5, I'd try it.
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Old May 30, 2017, 07:19 PM   #14
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In my F-CLASS rifle for 1k yards, I shoot 225 gr hornady ELD-m... Taking into account velocity and BC changes with slight weight variation, it takes 0.6 gr to change POI by 1" at 1000 yards or approximately 1/4 of 1%. In my hunting rifle 1/2 of 1%. Almost all premium bullets I have weighed fell into the 1/4 of 1% category.

If I was shooting 300 yards or less, I wouldn't bother
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Old May 30, 2017, 08:05 PM   #15
hounddawg
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learned something new today. I never thought to break it down with a ballistics calculator. Even bulk bullets seem to be within .2 grains
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Old May 31, 2017, 08:37 AM   #16
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OCD Overload

I admit I have have weighed the bullets and the cases. There were used in matches and for hunting.
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Old May 31, 2017, 09:07 AM   #17
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Quote:
Even bulk bullets seem to be within .2 grains

It's all relative. +/- 0.2 gr is good for a 225 gr bullet...That's about 0.22%. but in a 69 gr bullet, that would be 0.72%.

But, at the same time, you likely won't be shooting a 69 gr bullet 1000 yards.

The biggest thing that weighing bullets does is find extreme outliers.

While recently sorting 200 nosler 200gr Accubonds, I set the tolerances to 199.8-200.2 gr. I found 1 bullet at 198.6 with a deformed tip, and one bullet 199.1 with a groove in the boat tail so they were culled for use as bore foulers.
I have also been sorting matchkings and found a 168 gr in a box of 175's.....These scenarios are the true value in weight checking. 1" difference at 1k yards, even in my F-CLASS rifle is marginally remarkable. More trigger time will have a greater impact on accuracy I.E learning to read wind better, and getting the load accurately doped out to the distances you intend to shoot in different weather conditions.

So in summary, I do check the wight but I set a tolerance which will include 99% of the bullets and my main objective is to ensure there are no outliers
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Old May 31, 2017, 09:33 AM   #18
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I do weigh for accuracy loads, finding exactly what the OP found.
When in the Marine Corps, we weighed every bullet for the accuracy loads, and I continued that practice.
We used Sierra Match King bullets most times, and about half got rejected for weight or size/out of round, became 'Practice' ammo or went back to the manufacturer.

I weigh bullets and I also size bullets (drop through gauge) to make sure my accuracy loads are as consistant as possible.

Right now, the 'Reasonable Priced' consistant bullet is Hornady,
Only about half of them get kicked into the 'Range Ammo' bins...
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Old May 31, 2017, 10:06 AM   #19
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Twins...

I wouldn't bother with weighing PPU bullets.. IMHO, I would be more concerned about the construction of the bullets.

PPU bullets are more of a bulk design, IE .. good enough will do in production.

A match grade bullet, weighed and sorted might yield better results.. with its more QC and attention to important details. ( Concentric jackets )

I would suggest you try some Nosler Ballistic tips compared to your PPU's ... I think the odds would be more in your favor.

Here are some seconds for a reasonable price... ( Blems; Cosmetic Blemishes: Minor discoloration/oxidation of product or scratches on product. These blemishes will not affect performance. )

http://www.shootersproshop.com/nosle...lem-100ct.html

Or try some different weights...

http://www.shootersproshop.com/nosle.../isAjax/1.html
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Old June 3, 2017, 02:13 PM   #20
Mad_Max
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Sierra 30 Cal MatchKing HPBT

Today I weighed a box of 100 Sierra MatchKing HPBT and here are the results with the lightest being 167.9 GR. and the heaviest being 168.2 GR. a difference of .3 GR.:

100 Sierra 30 Cal .308 DIA
168 GR. MatchKing HPBT

WT. QT.
167.9 GR. 13
168.0 GR. 33
168.1 GR. 47
168.2 GR. 7
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Old June 4, 2017, 12:28 PM   #21
ShootistPRS
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Just a tad over .1% (1 tenth of 1 percent) maximum deviation from 168 grains.
I've seen less variation but still, it's not bad.
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Old June 8, 2017, 09:00 PM   #22
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I get really terrified when I think that two bullets might weigh exactly the same but could be unbalanced by a difference in concentricity. Now I not only have to weigh 'em, I have to spin 'em before loading.
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