load data-old vs new

[cephas53]

Howdy, am mentally stuck over new load data. Have a 280 rem that for about a decade was my only rifle. Have loads worked up for just about anything I'd want to do with it. Of course all my loads are now over max with the new data. Tried working up with new data but not as good as old loads. Worked with them side by side. Went out on a limb and worked up new powder with my old data. Got the results I would of expected if new data hadn't changed. Extraction good, primers look same, case measurements show no problem. Do need to chrono. So all in all I'm good to go with my old data. However there has been this little nagging, wondering thought in the back of my head...ever happen to anyone else? FYI powder IMR 4350.

[spqrzilla]

The quality of ballistic lab equipment, and its drop in cost, mean that a lot of data is getting better tested today.

Given how much the sources of our powders have changed - not merely different factories but different countries in some cases - I tend to respect the powder manufacturers data changes myself. Even if the old data was working for me.

I also load more conservatively than I used to. Don't feel the need to run at the ragged edge of pressure like I did when I was younger.

That said, the proof of the pudding is in the eating. If you've carefully reexamined your loads with recent powders, have fun.

[atr]

Interesting because I was just wondering about the old vs new data myself....my manuals from the late 1960 are different from my manuals of the late 80's,,,,which are different from todays manuals.....comparisons being made with the same powder/manuf.
My thinking has been that since I have loaded successfully with the data from the 1960's manuals, without any adverse consequesnce I will continue to use that data. Like my Dad used to say; "if its not broken don't try to fix it".
The current new data has taken into account new powders and manufactures, so whenever I load with these newer components I use the newer load data.
Finally, over the years I have found that maximum loading seldom produces the most accurate loads and I have developed the habit of starting at the low end of the performance scale and working up to the most accurate loading.

[telebasher]

Howdy, am mentally stuck over new load data. Have a 280 rem that for about a decade was my only rifle. Have loads worked up for just about anything I'd want to do with it. Of course all my loads are now over max with the new data. Tried working up with new data but not as good as old loads. Worked with them side by side. Went out on a limb and worked up new powder with my old data. Got the results I would of expected if new data hadn't changed. Extraction good, primers look same, case measurements show no problem. Do need to chrono. So all in all I'm good to go with my old data. However there has been this little nagging, wondering thought in the back of my head...ever happen to anyone else? FYI powder IMR 4350.

I think that part of the problem is that some powders have been "tweaked" so that their burn rates are different and can cause significant pressure spikes... hence the new lower max loads. How old is your lot of 4350? Maybe it is the same as the old load data... just thinkin' out loud. If your powder in your rifle shows no signs of high pressure it is okay in that rifle. When you buy a new lot of powder start low and work up.

[cephas53]

Good question, anybody know how to tell manufacturing date of powder by numbers on the can? The loads I'm using according to the old data are not max, but over what they have as max now. However they seem to be the sweet spot for this rifle.

[felix]

Lot number is the date and plant that produced the powder. Years ago that was true, so assume it is still true. That means you need to call the nearest source of the powder and work up the chain until the lot number can be deciphered. ... felix

[telebasher]

When I get a new container of powder whether a pound or 8 pounder I date it with a magic marker, same for primers too! That way I can use the oldest up first.

[felix]

When I get a new container of powder whether a pound or 8 pounder I date it with a magic marker, same for primers too! That way I can use the oldest up first.


That would be true only if you purchased directly from the manufacturer having no warehouse. Unless you know when the stuff was made and how it was stored throughout the retail chain, you have no idea how "old" the stuff really is. A warehouse changing temps from day and night, is worse than a warehouse at a constant hot temp. ... felix

[cephas53]

Will check with them to see if there is a way anyone could tell by the numbers on the can. Another way may be anyone remember when IMR was $15 a can out of a gun shop? :) Still had the tag on it.

[MtGun44]

Much (almost all) of the old data from powder makers was done with crude pressure
estimation methods. This is not necessarily unsafe data, but now that piezoelectric
and strain gage pressure systems are available, we can see that some of the old load
data was well above the intended max pressure.

The general intent was to run modern rifles somewhere around 50,000 psi (some
cartridges were higher) and have a proof load somewhere around 75,000 psi (these
are not hard numbers, just general concept for sake of discussion). So any gun that
was proofed to 75,000 would clearly function at 75,000 psi. It turns out that some of
the "good" data was really somewhere well above the intended 50,000 and even well
on the way to 75,000. Does that mean that old data will blow up your gun? Probably
not, but if newer data shows a lower max, it probably means that the older max was
found to be more like 60-65,000 psi when tested with newer equipment.

Will 65,000 psi load blow up your gun? Unlikely, but you are using up some of your
margins. If you normally run at 80 mph at night in the rain on worn out tires and think
it is OK, then running up on the ragged edge with loading data may be OK, too. As I have
gotten older (I like to think wiser, but maybe it is just more risk averse) I tend to push the
limits on everything a good bit less than I used to.

Bill

[BOOM BOOM]

HI,
The old Pacific Manuel had a reputation of blowing up guns. So I might be shy of using it's max loads.
That said I will NOT!!! use Lyman book listed minimum loads for IMR4350 or 4320.
Many reports came to NRA of S.E.E's doing this. It happened to me 2X's with book listed mim. loads, before I read the reports.
I am lucky to still be able to see, & still have both hands with all fingers attached.
Guardian angles were working overtime. So I'm still alive. Thank the LORD.
OH,YEAH,I later pulled the remaining loads to check to see if I made a load mistake. I did not.

[376Steyr]

The older the data, the more likely things have changed. Personally, I tried to replicate a 300 Win Mag load using IMR 4350 that had worked fine for my Dad in 1965. Using his old rifle, the flat primers and shiny ejector mark on the case head told me it was way too hot for the case, bullet, and lot of powder I had. His load was listed as Maximum in his old Speer manual, but is now several grains over the published maximum. The moral of the story? Work up to a load that's safe in your rifle, recheck it if changing the lot of powder, and be especially wary of "old" data.

[Larry Gibson]

As already mentioned most of the change is a result of the better pressure measuring systems that measure the pressure curve, not just the peak pressure as the old CUP system did. Also most older manuals used loads worked up in factory rifles, not pressure guns, as you and I work them up. They also used CHE for a few years until it was found to be quite unreliable. Most all current load data are worked up in presure guns with peizo inducers or strain gauges to stay within SAAMI psecs for the cartridge regardless of the action used in. Much of current data is also additionally tested in factory rifles using strain gauges. In other words the data is more complete and more reliable.

Now to address your .280 Rem specifically. Old data was worked up in numerous ways and may or may not be correct. New data is restricted to SAAMI's PMAP of 60,000 psi (Peizo/strain gauge not CUP). Thus if you are using an action that also handles the .270, .308W, standard magnums and any of the newer magnums which all have SAAMI PMAPs of 62-65,000 psi then you have to ask yourself is there any harm loading the .280 Rem to the same PMAP in such and action (a M700 Remington for example).

The problem is; without the ability to measure the psi of your loads in your rifle how do you know? You don't is the correct answer. If you dillegently worked up your loads (appears you have) and have been safely using them in all conditions then you're probably alright with them. Chronographing your loads and then comparing your velocities with similar published velocities using the same powder with the same weight bullets (preferably the same bullets) out of similar barrel lengths will give you an indication of psi along with all the other usual indicators we reloaders use.

Manuals are guides, However if in doubt don't excede published data is my advise.

Larry Gibson

[Char-Gar]

Here is my opinion on the subject at hand. Other won't agree and some will probably be irritated but here goes anyway.

Loading books are good things and should be taken seriously. But for the seasoned reloader they are not holy writ. They should be our helpers and not our masters.

Testing equipment, legal issues and many other items will show up as differences in data from time to time for the same source.

I am not one of those who think that components don't change all that much over time. UNLESS the makers says they are new, improved or reformulated. Powders vary from lot to lot and commercial loaders who buy by the barrel, test each new lot and massage the charge weight to keep the same velocities as the specs. So, old data may be a hair off from new data, because it comes from different lots.

This variation of powder from lot to lot is one reason loading books give starting loads and max loads. I am not a fan of max loads and certainly not of over max loads. If you are pushing the red line, best back off and work up again when you change powder lots, no matter what new data says. If you use less than max loads, you can whistle down the road in bliss for generations with the same data.. again..unless new, improved or reformulated.

[Mark]

Mike Daily of Hodgdon wrote a response to a similar question about 231 here:
http://smith-wessonforum.com/reloading/163307-changes-231-charges.html
Interesting.
Mark

[leadman]

Very interesting post from Mike Daly.

[spqrzilla]

Notice how no one wants to listen to his fine explanation on that forum?

[Char-Gar]

I read that post and it makes sense to me.

[Rocky Raab]

Lots of internet people don't want to listen to anybody who contradicts their pet theory. Some cling to the "lawyered down" idea, some to the claim that old pressure measurements were as good as today's, and some to the boast that they are simply smarter than the lab experts.

About the only thing that anybody can legitimately claim is that the loads they are using haven't damaged their gun - yet. However, using hot loads is like bending a coat hanger: You can do it quite a few times before something breaks, but it WILL break.

In the case of a gun, when it finally breaks you will have your hands and head near it.

[atr]

I thought that post by Mike Daly was a very good explanation....thanks for suggesting it.

[cephas53]

Good link, thanks. Have been looking at loads across the net and in more than several current manuals. Was unable to get through to IMR, but did have a good conversation with a tech at Sierra bullets. Ran some over the chrono and they are indeed in the same range as my original loads. Just an observation, but for reasons already stated, max loads vary from source to source. So it appears taking the specific bullet into consideration is more important than ever. Plan to work with it some this winter utilizing IMRs newest data, and work up a good cast load for it. You'ns have a good one!

[BOOM BOOM]

HI,
Remember some powders are very temperature sensitive. Your winter load may give much higher pressures in summer.:Fire::Fire:

[340six]

Notice how no one wants to listen to his fine explanation on that forum?
I agree[smilie=b:
Just to name one Lymans test data is just that Lyman's 49th ed test data take it for what it is worth. It is with their cast bullets with their alloy, primers mentioned,brass under their conditions.
Winchester has their own as well as many others.
:killingpc