So, if I buy new powder I use new data; if I use old powder I use old data?

I am not sure which powders have changed and which have not, I don't use more than about twenty out of all the variety available. The powder manufacturers all offer free data so it shouldn't be too hard to look at your old data and compare it to the latest data to make a determination.

If powders changed (burn rates?) very much, if any, they couldn't keep calling them the same names. And it's ironic that the changes in load data have all decreased. I think most of the reason is they have become a lot more lawyer leary.

Buddy, if you think powders don't change then you need to age some more yourself...Every day there are changes and that's why
all manuals reccommend getting new additions regularly..I've got
some that are over 40 yrs old and they are much different that
the ones I use now..and I check my loads on a chrono and watch
the pressure...and I'm not afraide to load'm hot..I still shoot
mostly magnums, except for my 308 and 2-250...which is hot anyway....Sounds like you just do not wish to spend the bucks for
a new manual..Dirt

Lawyer leary? That's a pretty safe bet. Powders don't change? That's a BAD bet and I'd hate to have to pay up and odds are 100 to 1 you'd lose.

Ok I'm comparing my Speer #11 and #13.

On a .38 special +P 140 grn bullet, it says to use in the #11 book, a max of 5.9 grns of Unique. That's a hot load. In the Speer #13 it is 5.3 grns. That is .6 grns on a really fast burning powder. That's a big difference.

On a .308 165 grn #11 book says to use 53 grns of 760 for 2631 fps and the new books says to use 51 grns of 760 for 2679 FPS.

2 grns less and more velocity.

On a 168 grn match Bullet the numbers are 53 grns of 760 for the old and 49 for the new. That is 4 grns difference. That is one caliber and 1 bullet and 1 powder.

They are all different. Some more than others. The point is, if you buy new powder get the new book or get the latest data online from the powder manufacture and use that.

Or don't. Just don't shoot around other people if you don't.

books are 5 years or more apart in printing. probably takes up to a year just to publish the latest.

powder is made and shipped daily.

Yes there are lot to lot variations in powder. And every time data is tested by whatever company is doing so, different equipment is used, different test barrels, different methods, different projectiles, different temperature, atmospheric conditions and so on so data will be different. Published load data is not meant to be a Bible, but to be a guide. If major changes in powder or the burn rates of said powder changed they wouldn't and couldn't keep calling them the same name as years before. Powder companies are not hesitant about introducing new and improved powders once they are developed and the ole standby powders of years past are "pretty much" as before.

Well then, use the old data...knock yerself out. I just want to know where you shoot so I can arrange to not be there while you're at it.

First of all I ain't your buddy. Never met you. Got chrono, know pressure signs, got the new book. In looking at the new manual I noticed that I have been loading a good bit over max according to them (new manual) with never a problem or pressure sign. What if the new guy buys an old manual at a garage sale and has at it?

It all depends on the rifle, one bore maybe tighter than the other, one chamber maybe a bit loose. Everything comes into play, the specific bullet you are using not just weight of the bullet.

Yeah I think thats a bad idea and I would go with the people who put out the informations advice.


I recently read and article where a gun writter had a friend show up with a new .270 and they loaded rounds with his "good old best load" of 4350 from 1965; the first shot had such high pressure they had to tap the casing out with a rod and hammer.

his words exactly "I dont know why we just went with it and didnt check the current load data!"

I cant remember the exact number but it came out to be a 40ish percent over load.....basically a proofing round

Novice question here, don't slap me down. Has the quality of brass in the casing changed over the years? Could another variable be just the strength/thickness of the brass now as compared to years back? I know for example engine blocks aren't as strong now as they used to be because some engine builders use cheap recycled steel instead of fresh iron. Could this be the case for the brass?

Quality of the brass would have nothing to do with the amount of pressure exerted in the chamber. There are thick and thin brands of the same caliber brass however. Thicker brass would have slightly higher pressures due to less space in the cartridge.

The metallurgy of the brass can have an effect on at what pressure it fails. I witnessed a bad batch of FACTORY ammo from Hornady fail and blow out an extractor. I told my buddy to send it back which he did and to hornady's credit they sent new(more than he sent them) and offered to repair any damage but what surprised me was they told him that it was a bad batch of too soft brass once they got it back and checked it.

All this talk of old data vs new data always reminds me of Jack O'Connor. If you have read all his stuff I think I know what he would call all you guys who feel like if you deviate even slightly from what the manual( GOSPEL) tells you then you will certainly be blown into a small pieces along with everyone for 3 city blocks.
I wouldn't call you that but he would!

See this thread!

The sky is falling. Most barrel failures do not come from shooting a rifle caliber 2 grains over max load.

This may be true...for bolt-action rifles, at least. Nonetheless, if you're not going to heed the recommended maximum charges you are flirting with disaster and you are probably doing it for very little in return. The velocity increases you get are not proportional to the increases in pressure so it's a game of diminishing returns. Without having very specific and well based reasons for exceeding the recommended maximums it should NOT be done.

Really...I think arguing anymore about this is pointless. The subject is what I think I will in the future refer to as a Darwinian pivot point.

Yep.

I would not recommend anyone load over the recommended maximum either...... the problem is which recommended maximum will you heed. If 6 manuals give you say from 40gr to 45gr as a maximum if you load 41gr you ARE over maximum.

Is the discussion pointless.... Well it can be but with folks like yourself's that have a rational debate it will be helpful to newbies I am hopeful. They need to realize that what is in every manual is a guide not the gospel.

It may have been stated but maybe the steel in out firearms isn't as good as it used to be ?.Just food for thought.