Bullet Production and Quality Control

[fx77]

Recently I purchased 500 bullets from a boutique specialist maker all of which were marked 105 gr

I found that loading them in my seating die led to inconsistent OAL measrements

I randomly selected 20 bullets of the 500 and weighed them

Of the 20, 13 were 104.9-105.2gr

Then measured the base to ogive on a bullet comparator, and the same 20 bullets had a range of .0040 (55-95 thou)from shortest to longest at the ogive ( distribution was bimodal at 25 and 95 thou)

In Contrast:


Berger bullets 105 gr 6 mm had one half the variability of weight compared to my other brand (15/20 were exactly 105.0, 3/20 were 104.9, and 2/20 were 105.1 gr) and length from ogive to base was on the money for measurements to 0.0005 and only 7/20 from the box of 500 that I measured ,were less than the others by .0005" and none was greater. Admittedly this was not free of Alpha or Beta error and was not power tested

, but just an observation
But seems a large commercial product is satisfactory, and in one case more reliable.

Questions:
1. Is this normal and acceptable?

2. Is my expectation for more consistency unreasonable?

3. If this is normal , how do you insure every seating is exact to the OAL for your chamber where it shoots most accurately? Must you seat long and creep up on the measurement?



Your expertise and vast experience are most appreciated.

 

[group therapy]

tag

 

[K22]

What is your shooting discipline? Benchrest, F Class, Hunting, etc.

I can't comment on bullet weight variation - never in 50 years of reloading have I weighed bullets. The following comments are on your OAL questions.

What kind of performance results are you obtaining with your reloads? Is the reason for the question to address a performance issue or just to produce a more consistent OAL?

Regarding, ogive variations, I have experience a few .001" within lot variation even with Sierra and Nosler hunting bullets which I consider premier hunting bullets. Consequently, I've never been able to seat a bullet to an "exact" OAL for every single bullet in a box. A lot are the same, but some vary a .001 or .002". However, I never found this to be a performance issue that I could detect but my discipline is precision varmint hunting shooting in the 1/2 moa or thereabouts area.

 

[fx77]

Benchrest Discipline

 

[Dusty Stevens]

Hows the OAL? Thats what matters.
Looks like you should stick to bergers. I dont have any to compare with

 

[fx77]

If the oal of bullets are irregular so will be the loaded cartridge unless u load long and adjust the die esch case to achieve uniformity
That is a PITA

 

[ronsatspokane]

I would expect more consistency, but since Berger no longer makes bullets (as far as anyone looking for them can tell) you are essentially measuring bullets against unicorn farts. I can't shoot unicorn farts.

 

[BartsBullets]

If the oal of bullets are irregular so will be the loaded cartridge unless u load long and adjust the die esch case to achieve uniformity
That is a PITA

The bullet seater should seat off the the same place on the bullets ogive. If your seater is contacting (seating) the point or nose then you’ll have problems with consistency.

 

[Ray123]

I've already shot the brand it shoots good I don't generally weigh bullets...check a couple to see if they are what the box says, then load for that bullet weight and shoot. Same way I load Bergers, box says 108 check 1 for weight and load for 108. Don't check base to ogive and but do a few on OAL...the first bullet of 500 to make sure I don't jam into the lands...gave that up over 30 yrs ago. On auto loader make sure they fit the mag. I shot 13, 5 shot groups with the 6 dasher 3 powders 105, Berger, 107 SMK, 108 Berger, 108 eldm, 110 SMK 105 RDF, 115 RDF, 115 Dtac. Don't break in barrels, I machine my own chambers in blanks, just polish the bore after checking with bore scope. Don't clean rifles at the range. This new Dasher barrel averaged. 313" for the 13, 5 shot groups with all those bullets first time out. None shot bad...in brand new brass ...and I never weighed em or sorted em in any way, and I know they varied in OAL. Philosophy...if it don't matter on the target it don't matter to me. ..and factory 2nds bullets work fine for killing big game with large bore 338, 350, 416, magnums at reasonable ranges and plinking, unless ya use the small hunting callibers, then premium bullets are a plus. Simplify...if it fits.

 

[JMayo]

When i shot bergers I sorted by weight then sorted by ogive when i was ready to load them. Trying to keep alikes together.

I don't think the weight difference op mentioned is significant (scale abilities aside)
But i do think base to ogive is important and I'd sort to keep "alikes" together.

May not mean much to others but it does to me.
I'll play with my toys the way i want to !

 

[fx77]

The bullet seater should seat off the the same place on the bullets ogive. If your seater is contacting (seating) the point or nose then you’ll have problems with consistency.

Good point'Using a Short Actions Custom Seater with Mitutoyo top...so is it the seater or the bullet?
Have the same issue with a Whidden Seater.
Thanks.

 

[rwj]

Good point'Using a Short Actions Custom Seater with Mitutoyo top...so is it the seater or the bullet?
Have the same issue with a Whidden Seater.
Thanks.

It’s possible that the internal profile of the seating stems doesn’t match that of the bullet nose. You cited 105 grain 6mm bullets in your original post which likely means they have a VLD (long slender) nose profile that requires a matching VLD seating stem for contact to occur near the bullet ogive as @BartsBullets noted above. Most die suppliers can provide VLD stems…

 

[fx77]

Thanks that is something to research

 

[fx77]

If the variability in base to ogive is present in comparator measurements, it does not matter where the ogive fits on the bullet seating stem . The seating stem seats the bullet, but if there is a difference in the virgin bullet from base to ogive, and the stem sits on the ogive,it will be reflected in the final OAL of the bullet.
Thus is not the error carried forward for each bullets lack of uniformity?

 

[BartsBullets]

If the variability in base to ogive is present in comparator measurements, it does not matter where the ogive fits on the bullet seating stem . The seating stem seats the bullet, but if there is a difference in the virgin bullet from base to ogive, and the stem sits on the ogive,it will be reflected in the final OAL of the bullet.
Thus is not the error carried forward for each bullets lack of uniformity?

If you want overall length the same once the bullet is seated, then sort your bullets by Overall length.

The seater stem should contact the exact same place (diameter) on your bullets and seat them to the same place (ogive wise). EVEN IF your base to Ogive measurement varies from bullet to bullet. The difference in the bullet is in the back of the bullet (NOT THE OGIVE). I’ve been through this many times. Your seated bullets should be within .001 even if the bullets bto for individual bullets is different. I’m not talking overall lenght here. So after you load a couple of bullets use you bto comparator on that. If your measurements vary there, more than likely have a problem with your seater stem.

Bart

 

[fx77]

If you want overall length the same once the bullet is seated, then sort your bullets by Overall length.

The seater stem should contact the exact same place (diameter) on your bullets and seat them to the same place (ogive wise). EVEN IF your base to Ogive measurement varies from bullet to bullet. The difference in the bullet is in the back of the bullet (NOT THE OGIVE). I’ve been through this many times. Your seated bullets should be within .001 even if the bullets bto for individual bullets is different. I’m not talking overall lenght here. So after you load a couple of bullets use you bto comparator on that. If your measurements vary there, more than likely have a problem with your seater stem.

Bart

So regardless of the bullet manufacturer ,and if you want the OAL to ogive in your chambers to be the same, U must presort by length to ogive your bullets before seating. Thanks for the clarity.

 

[BartsBullets]

So regardless of the bullet manufacturer ,and if you want the OAL to ogive in your chambers to be the same, U must presort by length to ogive your bullets before seating. Thanks for the clarity.

Yep

 

[Ned Ludd]

I've posted this several times in the past few months, but once more isn't going to hurt. What Bart is describing is illustrated visually in the image below. In my hands, there is usually noticeably more bullet length variance in the nose region than in the boattail or bearing surface segments. The two most critical points on the bullet for consistent/uniform seating depth are 1) where the seating die stem contacts the bullet nose out toward the meplat, and 2) where the caliper insert seats just above the bullet bearing surface close to where the bullet will first contact the rifling. If there is length variance in the bullet nose region where these two critical points reside, sorting bullets by base-to-ogive, which lies outside of these two critical contact points will not make the seating depth more uniform at a single single seating die micrometer setting. Seating depth will still vary by whatever bullet nose length variance lies between the two critical contact points.

So sorting bullets by OAL can improve the consistency of COAL in a way that sorting by BTO will not just as Bart noted, because there is usually more length variance in the nose region, at least in my hands. However, it can also serve to improve the consistency of seating depth because sorting bullets by OAL is really not all that different than sorting by nose length, which is where the majority of length variance, as well as the two critical contact points lie. Bob Green and perhaps a few others make a tool/comparator for length sorting bullets specifically in the nose region. One can also do approximately the same thing using a combination of calipers and subtraction, but most don't because it's extra work and perhaps not as accurate. Sorting bullets by OAL is about as easy and straightforward as any kind of sorting we might ever do.