going to a new lot number on powder where to start

R

rickyb

New member
I have a really good load for my 25/06 and it's 53.5g of H4381SC. I have just finished off what I had left of the powder. So the next batch I get will be a whole new lot number. Everything else is the same with the bullets, primers ect. I have read where I should drop down 5% and work back up since I'm close to max. Have you guys ever saw a big difference when you change lot numbers and worked back up?
 
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If it's a hot Max load you may want to load a couple of rounds 1.0 gr lower and a couple the same and check before stoking up a bunch. If your load is mild then personally I would not be too concerned. That's just me.
 
Everyone will tell you to drop back and work up again. My experience of 30+ years has shown that it is pretty much a waste of time.

Powder comes in burn rates, if the burn rate changes it is not the same powder. A friend also experimented with Unique that he had for 20 years and a newly acquired batch. When run over the chrono there was no difference between the 2 lots when all other components were the same.

This is my experience, someone will probably come along and tell me I'm evil and nuts.
 
Originally Posted By: joedEveryone will tell you to drop back and work up again. My experience of 30+ years has shown that it is pretty much a waste of time.

Powder comes in burn rates, if the burn rate changes it is not the same powder. A friend also experimented with Unique that he had for 20 years and a newly acquired batch. When run over the chrono there was no difference between the 2 lots when all other components were the same.

This is my experience, someone will probably come along and tell me I'm evil and nuts.

My experience in the last 40 years has been the same.
 
I've seen plenty of lot to lot variations. Enough to effect accuracy isn't unusual. Changes to powder dump settings to throw a given weight are common too. That's why I usually (but not always...) buy components in bulk so that I can wear out a barrel without worrying about having to change lots on anything.

Some powders have better reputations than others for lot to lot consistency, too.

Worst I ever personally experienced was with RL-22. Which is one that has a reputation for lot to lot variation. Was running 80's out of an 8 twist .22-250AI with it, got a new lot that most definitely required backing off of my previous load.

It happens... None of my business or concern what anyone else does though.

- DAA
 
I tend to agree that the lot to lot variation generally doesn't have a significant effect on the net result especially where max loads are Not concerned. However, I would agree with DAA when it comes to RL22. I've used it in a 257 Weatherby and noticed a large difference between lots. So much so, that I've changed the powder used for that round.
 
Thanks guys for the response. I think I will back off a grain and see if there are any pressure signs. I bought four pounds of powder today with same lot, my bullets and primers are same lot and 100 pieces of Norma brass that is the same lot so I think I will be OK. Just thought it was funny I shot my first three shot ragged hole and had used up about all the powder. I bought that pound of powder to work up a load for my buddies 25/06 a couple of years ago. Hopefully I can post a picture to show it. Thanks Rick
 
Originally Posted By: CastJust load up a few to try. No worries. What could possibly go wrong?

Not really what I would call sound advice, haha. I would say if it's a concern, back it up a grain and run a few at .2 increments.
 
Changing lot #'s can make a difference in how your load shoots. It may/may not in your situation, but it can. To find out go back and do a load sequence over the chrono comparing the old and the new. Like DAA, I've also seen noticeable differences from lot to lot. In one instance, previously ok loads in a MachIV were now blowing primer pockets. In another powder/cartridge there wasn't any real velocity difference per gr. powder, but accuracy was at a much different speed......about drove me nuts until I thought to check lot #'s and then remembered they were about 10yrs apart.
 
Where do you find the lot#?
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Long ago I switched to a new lot of 2400 in .357 magnum. I backed down to the STARTING load and blew the primer and etched the bolt face. It was a Desert Eagle pistol. One full grain less and still had primer leaks. Needless to say I always start over with any component change, even if it's just three rounds.
 
Originally Posted By: Rock KnockerWhere do you find the lot#?
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On the one pound jugs it shows what looks like a date and below the date is a 4 digit number. Don't know if this is the lot number but the four I just bought had the same date and four digit number so I going to hope they came from same batch.
 
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Originally Posted By: ninehorsesLong ago I switched to a new lot of 2400 in .357 magnum. I backed down to the STARTING load and blew the primer and etched the bolt face. It was a Desert Eagle pistol. One full grain less and still had primer leaks. Needless to say I always start over with any component change, even if it's just three rounds.

Oddly enough the only powder I have ever had do that was 2400. I had a huge amount I finally shot up and biught eight more pounds in 2001. Went to a match and had to pound the cases out of my 586. Needless to say I had a rough day. I won but my palm took a while to heal. I ended. Up about a grain and a half lower.

Greg
 
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