Bullet variation from lot to lot
- Thread starter hawk-i
- Start date
I've got 3 lots of Berger bullets on my bench that range almost 0.060 OAL and base to ogive from shortest to longest, all the same part number. the shortest ones shoot like a bastard in my target rifle, the longest ones absolutely suck and will sit there until I buy a barrel with a slightly faster twist, the weight of all of them is bang on.
is it normal? sadly yes, is it acceptable given the price point? absolutely not
is it normal? sadly yes, is it acceptable given the price point? absolutely not
Lot to lot variation is inevitable. Not all bullet are made out of the same dies. In Benchrest we sort bullet by weight and CBTO in the same lot.
This have been well know for decade to buy the same lot numbers. When you buy in 500 or 1000 thats what you achieve. Buying box by box is what you end up with.
But just think about .22 LR ammo…lot to lot variation is just nutz..
Just like the women we went out with, some do, some don't.
I've found Privi bullets to be some of the worst and frankly undependable, even out of the same bag.
Hornady/Speer and Sierra are usually very consistent between lots.
Still, you should shoot a few and check them out. They may be perfectly acceptable accuracy wise but POI may change by quite a bit.
If there is a significant change, make sure you check them out a different distances, some will change their trajectories as well.
I've found Privi bullets to be some of the worst and frankly undependable, even out of the same bag.
Hornady/Speer and Sierra are usually very consistent between lots.
Still, you should shoot a few and check them out. They may be perfectly acceptable accuracy wise but POI may change by quite a bit.
If there is a significant change, make sure you check them out a different distances, some will change their trajectories as well.
I think manufacturers produce ammo with some specific "acceptable" tolerances within a lot, or as overall "good-enough" accuracy to sell under their brands.
The characteristics within a lot are controllable, but not lot to lot. I think they test each lot, and if hyper consistent, the lot goes into the match bin.
Trying to make each lot perform like the last would be overly expensive.
The characteristics within a lot are controllable, but not lot to lot. I think they test each lot, and if hyper consistent, the lot goes into the match bin.
Trying to make each lot perform like the last would be overly expensive.
That may be the case with some manufacturers but there are industry standards as well that they should adhere to.
Back around three decades ago, a fellow by the name of Juenke developed a device that measured the birefringence of an electric charge on the bullet jacket, after it was formed.
This device, called a Juenke Gauge" was originally designed to be used on J4 jackets, used for match bullets.
It didn't take very long for commercial bullet makers to see the significant accuracy gains for bullets made with consisten jacket thickness all the way around.
They extrapolated the birefringence reading to thickness readings and this allowed them to adjust their swaging equipment so that the jacket thicknesses could consistently be kept to very tight tolerances.
Once this gauge became and industry standard setter, that could be measured, quickly and easily on the production lines, that's when we started seeing a lot of changes in bullet design from the traditional cup and core types.
There is a lot to this application and if you want to delve into it, check it out online.
Back around three decades ago, a fellow by the name of Juenke developed a device that measured the birefringence of an electric charge on the bullet jacket, after it was formed.
This device, called a Juenke Gauge" was originally designed to be used on J4 jackets, used for match bullets.
It didn't take very long for commercial bullet makers to see the significant accuracy gains for bullets made with consisten jacket thickness all the way around.
They extrapolated the birefringence reading to thickness readings and this allowed them to adjust their swaging equipment so that the jacket thicknesses could consistently be kept to very tight tolerances.
Once this gauge became and industry standard setter, that could be measured, quickly and easily on the production lines, that's when we started seeing a lot of changes in bullet design from the traditional cup and core types.
There is a lot to this application and if you want to delve into it, check it out online.
