variations in match bullet weights

[Oregondoug]

Reloading for accuracy/competition, and in weighing sierra Matchking 190g .30 cal bullets, I have a variation of between .1-.3 GRAMS (not grains) in the boxes of bullets. majority of them weigh 12.4 grams and some as high as 12.7, a few light at 12.3.
Would you competition guys consider this acceptable variation , and do you sort or not?
Thanks, Doug in Oregon

 

[jonbearman]

What does that mean in relation to grains?

 

[mr45man]

What does that mean in relation to grains?

A bunch of grains.

 

[Highpower-FClass]

A 6 grain difference (12.3 grams to 12.7 grams being 189.8 - 196 grains) is a lot. With Berger 30 caliber bullets I am typically seeing +- 0.3 grain, if that. I used to see a high variation with base to ogive for Sierra bullets. Bergers are much more consistent in my experience.

 

[Pumba]

1gram = 15.43grain

 

[davidpatton]

i dont use 30 cal bullets, but on my 6mm i have about .2 grain variation. As for the question of should you sort, yes! I think a span that broad in weight will cause a difference, but look at it this way- if you take the time to sort them you never have to wonder if sorting them would have given you a better group!

 

[DR1586]

I would double check my scale. That type of variation is way outside of what I've ever seen from Sierra or any other manufacturer. Heck, my deer hunting bullets are more consistent than that. Out of curiosity, why are you using grams as your unit of measure? Everything in our world is going to be measured in grains.

 

[Dusty Stevens]

Sierra wants to see those bullets. Give em a call. Thats way farther out than the cheapest blasting ammo from north korea

 

[Ned Ludd]

Grains to grams: multiply by 0.06479891 (approximately ). I agree with checking the scale. If that's really the weight variance within a lot of bullets, I'd be looking for a different manufacturer...quickly. Weight variance in the 4th decimal place (column) isn't going to affect your load. Variance in the third decimal place is really not where you want to be, that is very close to 2.5% variance. Although I usually only weigh bullets to cull out gross outliers, I'd strongly recommending a weight sort for that batch, prior to any other sorting you intend to do.

 

[dmoran]

With weight variations that large, I suspect the bullets may not be of the same Lot, or some other indirect reason.
Donovan

 

[Oregondoug]

All good comments. I'll calibrate both scales and see what I come up with. I used grams because I first sorted using a digital scale. I have always used Sierra, with good results, btw.

 

[Zero333]

Never seen such variance from Sierra nor any other manufacturer.

Even different lots don't explain 190smk's weighing 195.9 grains.

 

[amlevin]

With weight variations that large, I suspect the bullets may not be of the same Lot, or some other indirect reason.
Donovan

With variations that great I'd it's not the bullets that are suspect but rather the scale how the operator is reading it.

Even the crappiest bullets I've ever shot only vary by 3-4 grains MAX (as long as they come same mfr.).

 

[normmatzen]

YES!
What kind of scale are you using? If you have a lab balance with 0.001g resolution (1mg) you will have about 0.015grain resolution.

If you are using a balance with 0.1g resolution, you will have about 1.5grain resolution. Be aware, if you have a 0.1g resolution scale, most have accuracy and linearity of 0.1g as well so your accuracy is
only +/- 1.5 grain.
If you have a beam balance with 0.1g resolution the accuracy could be WAY off the 1.5grain number above!

 

[M-61]

All good comments. I'll calibrate both scales and see what I come up with. I used grams because I first sorted using a digital scale. I have always used Sierra, with good results, btw.

And I assume this digital scale did not have a "GRAINS" option?

 

[waldo1979]

Reloading for accuracy/competition, and in weighing sierra Matchking 190g .30 cal bullets, I have a variation of between .1-.3 GRAMS (not grains) in the boxes of bullets. majority of them weigh 12.4 grams and some as high as 12.7, a few light at 12.3.
Would you competition guys consider this acceptable variation , and do you sort or not?
Thanks, Doug in Oregon

Doug,

That's a bad batch for sure. Call Sierra and they will replace them. I've always had great results with SMKs being consistent (typically within 1% variance).

Are any of the bullets discolored or corodded? My friend recieved a bad batch of SMK that were water damaged. Sierra sent out a new batch no questions asked.