"Lot Speak" Question on Speed

[shoot4fun]

All the quality 22LR ammo I buy is by the brick (10 boxes) and all that ten will be same lot number.
Now and again I see those "in the know" rimfire guys express (when asked) the lot number as a "Speed" number (example 25 speed) instead of the printed lot number. The lot testing targets I have seen from some Anschutz rifles have all been labeled with numbers such as 033, 036, 029, etc.
Is there a place inside that long lot number that I should key on as a "speed number"?

 

[snert]

Following

 

[Ccrider]

Lapua Rimfire Lot Numbers​

Home » Knowledge Base » Lapua Rimfire Lot Numbers
Current Lapua rimfire ammo lot numbers are composed of eleven (11) digits, five (5) digits followed by a forward slash, followed by another six (6) digits.
The five digits before before the forward slash:

• First two digits (digits 1 and 2): Prepend a ‘3’ in front of the digits to get muzzle Velocity in meters per second. Example: If first two digits are 27, then the muzzle velocity is 327 meters per second.
• The last two digits (digits 4 and 5): Year of production code. 54 = 2019, 55 = 2020, etc.

The six digits after the forward slash is the actual lot number (assumed to increment sequentially).

 

[snert]

well there ya go...learning a new thing daily! Thanks

 

[shoot4fun]

Lapua Rimfire Lot Numbers​

Home » Knowledge Base » Lapua Rimfire Lot Numbers
Current Lapua rimfire ammo lot numbers are composed of eleven (11) digits, five (5) digits followed by a forward slash, followed by another six (6) digits.
The five digits before before the forward slash:

• First two digits (digits 1 and 2): Prepend a ‘3’ in front of the digits to get muzzle Velocity in meters per second. Example: If first two digits are 27, then the muzzle velocity is 327 meters per second.
• The last two digits (digits 4 and 5): Year of production code. 54 = 2019, 55 = 2020, etc.

The six digits after the forward slash is the actual lot number (assumed to increment sequentially).

Thank you my friend!
The meters per second makes the whole mystery clear.
All I would need to do is use one of the online conversion sites to get the FPS numbers.

 

[jpx2rk]

If you go to Killough's and click on one of the match level ammo options, such as Tenex or Black Box, you'll see various lot #'s listed in a drop down menu. In the lot # info the "@1077" is the average speed IIRC for that particular lot. There will still be the variances between the individual rounds, along with ES/SD variances as well between the rounds and even the boxes.

If you find some ammo that you rifle/gun shoots really well, buy all you can and more if possible. LOL

 

[tmwinds]

3.281 x m/s = fps

 

[Ccrider]

Thank you my friend!
The meters per second makes the whole mystery clear.
All I would need to do is use one of the online conversion sites to get the FPS numbers.

You are welcome. I had the same question when I sent my Vudoo to the test facility. Found the answer on a website.

 

[grauhanen]

The "speed" indicated on the box by the manufacturer may not be the speed in your rifle. In fact, some "slower" speeds can be faster than those that are supposed to be faster and vise versa.

With .22LR match ammo "speed" is not relevant to performance.

 

[BCR1]

What about SK numbers? Some say the first two/ three numbers are the week (first two) or day (first three) of the year( last two numbers) when it was made. All I know is that a higher first two numbers in the SK line shoot better for me than a lower first two numbers so I equate that with speed, not production dates.

Bill

 

[grauhanen]

What about SK numbers? Some say the first two/ three numbers are the week (first two) or day (first three) of the year( last two numbers) when it was made. All I know is that a higher first two numbers in the SK line shoot better for me than a lower first two numbers so I equate that with speed, not production dates.

In 2020 a fellow posted on RFC the following information which was based on an email reply he received from the manufacturer.

Here is a breakdown of the SK lot numbering for you:
example lot # 08553/21491
-First 3 numbers (085) is the day it was made so 85th day of work
-Second two numbers (53) is the year. "53" is 2018, "54" is 2019, etc. /
-First number (2) is the loading line it was made on
-Next 3 numbers (149) is the lot made by that line
-Last number (1) is the sublot, should range from 1-4.

See post #5 https://www.rimfirecentral.com/threads/sk-ammo.1190173/

 

[dgeesaman]

I thought about posting that I didn't see any benefit to picking lots based on the factory speed rating, but I realized I had data that might inform my opinion. So here it is. I took the first two digits of the lot numbers (converted to FPS) during two visits to the Lapua test tunnel and plotted the 50m 9- or 10- shot group size (outside-to-outside, mm) for each rifle.

Some rifles showed a general trend toward slower or faster ammo, (but not too slow!) that suggests if I have to pick ammo knowing the factory lot speed, I can at least improve my chances at obtaining excellent accuracy. But the correlation is weak and some rifles didn't show any preference for ammo speed.

 

[VLNBYR]

Were these lots a mix of CX and Midas?

 

[TRSR8]

I thought about posting that I didn't see any benefit to picking lots based on the factory speed rating, but I realized I had data that might inform my opinion. So here it is. I took the first two digits of the lot numbers (converted to FPS) during two visits to the Lapua test tunnel and plotted the 50m 9- or 10- shot group size (outside-to-outside, mm) for each rifle.

Some rifles showed a general trend toward slower or faster ammo, (but not too slow!) that suggests if I have to pick ammo knowing the factory lot speed, I can at least improve my chances at obtaining excellent accuracy. But some rifles didn't show any preference for ammo speed.

As has been stated, repeatedly, speed has ZERO to do with lot quality. You pick specific speeds as your metric you’re chances go down, not up.

 

[dgeesaman]

As has been stated, repeatedly, speed has ZERO to do with lot quality. You pick specific speeds as your metric you’re chances go down, not up.

Look I know you're some champion shooter and all, but an opinion is not data. One is not better than the other. They both have value in different ways.

 

[dgeesaman]

Were these lots a mix of CX and Midas?

Yes. The 1907 was in Ohio in July 2020 and the others were August of this year.

Interestingly, the Center-X and Midas+ groups averaged the same size at 50m, 18.0 vs. 18.3mm.

 

[TRSR8]

Look I know you're some champion shooter and all, but an opinion is not data. One is not better than the other. They both have value in different ways.

Data? Friend, you don’t have data, you have coincidence. Guys, I know personally, guys that have won big matches, have done so shooting 1047fps-1075fps out of the same guns. How many veterans have to tell you the same thing before it sinks in?

 

[dgeesaman]

Data? Friend, you don’t have data, you have coincidence. Guys, I know personally, guys that have won big matches, have done so shooting 1047fps-1075fps out of the same guns. How many veterans have to tell you the same thing before it sinks in?

It seems you put a lot of effort on this board giving concise answers based on prevailing wisdom and you get frustrated that the discussion doesn't end as soon as you provided that answer. And you've apparently been doing that for long enough that now everything has been "stated repeatedly". That's a useful service you provide.

It's not the only way to look at things. I enjoy collecting my own data and comparing it to the tribal knowledge. If me sharing my data offends you, that's unfortunate but it's completely unrelated to your postings.

 

[Liven The Dream]

Time out.
Hit the Reset Button,

 

[TRSR8]

It seems you put a lot of effort on this board giving concise answers based on prevailing wisdom and you get frustrated that the discussion doesn't end as soon as you provided that answer. And you've apparently been doing that for long enough that now everything has been "stated repeatedly". That's a useful service you provide.

It's not the only way to look at things. I enjoy collecting my own data and comparing it to the tribal knowledge. If me sharing my data offends you, that's unfortunate but it's completely unrelated to your postings.

You misunderstand. If you go to RFBR sites, like RA you will find " stated repeated' is not by me but by virtually every long term, experienced, match winning shooter, that has years of experience picking good ammo, several of which refuse to weigh in on a thread like this with guys that insist on plowing old ground to their detriment. Lots of well established practices involved in the RF world. Good luck with the ammo.