What defines a lot? Is it the same for every manufacturer?
A lot is a production run of a certain amount but I don't know what that number is. I don't know that answer on #2.
Bill
What defines a production run? I'm not trying to be wise a** but I worked for manufacturing companies and there was not any industrial standard. Different lots of raw materials, different machines, different operators for critical operations, etc can all affect quality (consistency). I would guess the high end ammo mfgs consider all the pertinent factors to define a lot but surprised if the lower end stuff is as stringent.
Every ammo that I am aware of has a lot number. Don't care if it's shotgun shells, RF ammo of ANY quality, CF, etc. Quantity of said ammo lot number is the production run the MFG sets as to whatever they set it at, a single production run. That run can vary between MFGs.
On every box of ammo, there is a lot number. It's the only way the MFG can manage things when things go wrong.....ie, a recall of ammo that has presented some problem that the MFG does not want in consumers hands anymore.
In RF, lot numbers of the same type of ammo within a brand, can shoot vastly different in certain, or many guns. This is a well known fact for those that compete at the highest levels of various disciplines in RF competition, be it rimfire benchrest, position shooting, biathlon, pistol bulls eye shooting, etc. With this in mind, when testing RF ammo for best performance in YOUR gun, NEVER think of brands or types of certain brands, without understanding the variations of 'lots' within those brands or variations of those brands.
Earlier in the year my friend and I tested about 30 lots of Eley Match. So, all of it Eley, and all of it a certain type of one MFG. Out of all those lots, only two or three were of interest for us shooting ARA UL matches. Another thing of interest, a REALLY good lot is most likely going to shoot competitively in a lot of rifles, not just one or two, OR YOURS! Speed in delivery of test lots and speed in testing said lots is imperative to being able to buy before the lot is gone. A really good lot will disappear quite quickly, even before the current market of low to no inventories.
I read all these posts on several boards about "my rifle likes SK-RM", or "my rifle likes" this that or the other thing. BS, you found a lot of said ammo that tickles your expectations. The next lot of said brand/type in your rifle may very well shoot like dog poop, depending on your thoughts about what is 'good'. I test only Lapua and Eley. Tons of times I find ammo from either that does not match it's price point. Eley Match of a certain lot that out shoots the lots of Eley Tenex I shot at the same time. Same with Lapua CX and Midas+. It's lot numbers of ammo that the rifle likes most of the time. NOT the brand or type of brand. The only way to get the best for YOUR rifle is to test. The lot number is on every box! This how big time RFBR shooters shoot big time cards......along with a whole bunch of other stuff mixed in. I guarantee the best Factory Class ARA shooters are doing the same.
In general, Eley lots are typically larger batches than Lapua batches.
JME.....Scott