SAFETY WARNING to people who load for .500 S&W Magnum!

[John Ross]

SAFETY WARNING!

Many of you know I focus my development efforts on the .500 S&W. I have designed bullets, developed loads, done extensive testing, had the S&W factory pressure test my ammunition, and even had them build a limited production gun to my specifications. One S&W engineer flatly states that I have done more load development for this cartridge than either the S&W factory itself or the powder companies. I thought this last might be an exaggeration but after something I saw today, I'm not so sure.

I have been using the computer simulation Quickload and have found it to be very close in velocity and pressure predictions to the empirical results I have obtained both from my own chronograph sessions and S&W's pressure testing of ammunition that I loaded.

Whenever I see load data from a powder company that includes pressure figures (such as Hodgdon), I run the numbers through Quickload to see how they come out. In almost all cases the numbers agree pretty closely, but once in a while something makes me scratch my head a bit.

Well.

Yesterday I went over some new published data I hadn't seen before, and my hair stood on end. Go to http://www.accuratepowder.com/wp-con...2016_Web-1.pdf and scroll down to Page 21 for S&W .500 data.

I haven't checked every load with Quickload, but some of this data looks absolutely insane! Let's look at their data for the .500 using the Hornady 500 grain Jacketed Soft Point. They load this bullet to an OAL of 2.070".

They list pressure data only for max loads, not suggested "starting" loads.

4100 Powder
Starting load 28.3 grains and (according to Quickload) 39,700 PSI.
Max load 33.2 Gr. They say 52,300 PSI, QL says 64,200. Okay, I've doubtless loaded some rounds at this pressure...

Ramshot Enforcer
Starting load 28.3 grains and (according to Quickload) 45,200 PSI.
Max load 33.2 Gr. They say 52,300 PSI, QL says 73,000. This is starting to worry me...

Accurate 5744
Starting load 33.9 grains and (according to Quickload) 64,300 PSI. I don't like this...
Max load 39.9 Gr. They say 52,300 PSI, QL says 117,600. QL also puts this charge at 127% loading density(!)

Accurate 1680
Starting load 39.4 grains and (according to Quickload) 67,300 PSI. (115% loading density)
Max load 43.7 grains. They say 54,700 PSI, QL says 112,400. QL puts this charge at 128% loading density.

Okay, let's try the Cast Performance 440 grain WFN loaded to an OAL of 2.005" with these last two powders:

5744
Starting load 36.3 grains and (according to Quickload) 43,100 PSI. (107% loading density)
Max load 42.7 Gr. They say 55,400 PSI, QL says 89,600. QL puts this charge at 126% loading density.

1680
Starting load 42.7 grains and (according to Quickload) 89,500 PSI for a starting load! (126% loading density)
Max load 47.5 Gr. They say 47,750 PSI, QL says 182,900 PSI! QL puts this charge at 140% loading density. I am at a loss for words...

Somebody please double check my numbers...

[Don Purcell]

If it looks like a duck, walks like a duck, quacks like a duck... Since I know you have relied on Quickload with accurate results over the years then there should be little reason to believe these numbers are wrong. It's enough to turn your hair white.

[pmer]

I don't have a .500 but I suppose one could load a case to one of max charges and see it looks like it's at 140 % load density. (if you have some 1680 on hand...don't shoot it that way..LOL..)

[John Ross]

If it looks like a duck, walks like a duck, quacks like a duck... Since I know you have relied on Quickload with accurate results over the years...

Not exactly. I used a shareware DOS program from 1988 written by the now-deceased Louis Sayre called Suggest-A-Load to do estimations and assist in my .500 load development. It was (and is) very good, but Quickload takes things to a much higher level with its vast database of powders and their burning characteristics. I have been using Quickload for not quite a month.

Suggest-A-Load will ask you for all parameters including peak pressure and will give you suggested charge weights of a few powders. I found the results to be very close to empirical data. However, the program will not let you specify a peak pressure that is higher than 55,000 PSI. You also cannot ask it for results with specific powders--it selects them for you.

This is not really a bad thing, but you can't just input the data for someone else's load and see if it agrees with what they say the pressure was. You have to input the pressure and see if it comes up with a load that is similar.

Using SAL and inputting data for the 440 gr. Cast Performance bullet at an OAL of 2.005" and peak pressure of 55,000 PSI, it recommends a slightly compressed load of 35 grains of either H110 or 296 for a velocity of 1630 FPS and pressure of 52,300 PSI. H110/296 was the ONLY recommendation for powder that it gave me for a pressure level near 55,000 PSI using this bullet.

Inputting 35 gr. H110, 440 CP @OAL of 2.005" into Quickload results in 102% loading density and 51,500 PSI. Close enough for me, and very similar to empirical results reported by others.

This data supplied by the folks who actually make Accurate Powder really bothers me...

[Michael J. Spangler]

Subscribed

[BCB]

I don't have a .500 but I suppose one could load a case to one of max charges and see it looks like it's at 140 % load density. (if you have some 1680 on hand...don't shoot it that way..LOL..)

I agree with this. I have done the same thing...

Good-luck...BCB

[44MAG#1]

If you are concerned what I would do, if you haven't already, is get my data in order and call the manufacturer and tell them.
If you haven't already done this or your not going to then the concern would, to me, seem unwarranted or not important.
I know from use of AA1680 it take roughly 4 grains of it to equal H110 in the 500 S&W.
Could I be wrong oh yes. I seem to be wrong most of the time anyway. According to most that is.

[W.R.Buchanan]

I would start calling the Mfg's and get some more data that either supports or disputes your findings.

Quickload may be the problem.

Typically when many sources say one thing and then one disagrees, it is the one who disagrees that is at fault. (not talking about politics here!!!)

However sometimes it goes the other way, and that is where you must actually be able to confirm your findings with empirical tests, and more than one test facility should be used to confirm that.

All the powder Manufacturers have ballistic labs with pressure testing equipment that is used and calibrated daily. Everybody is using PSI as the measurement now so the results will eventually become consistent as CPU falls by the way side. That alone will get rid of many anomalies as most people don't know the difference between the two.

Lots of times Computer programs that use Algorithms to calculate data suffer from "algorithm wander" at the low and high ends of the range. In other words the algorithm has a sweet spot or area that it functions fine within, but as you get to the fringes it becomes less accurate. You can see this happening when the results go askew at the ends of the spectrum compared to other published data, which is linier in change.

Charge weight versus pressure is a pretty linier graph. If there are spikes in the pressure curve due to changes in charge weight chances are it is the program. Other factors can create spikes, but charge weight changes are generally linier in nature.

All things must be considered,,, and relying on one source for load data is not good practice. The reason why you cross reference data between sources is to find typos which occur simply because people enter the wrong numbers into the charts. Generally there is a disclaimer attached which states that you need to use caution.

Like I said at the start I would start contacting manufacturers and comparing their results with yours, and if you get consistent evidence that they are in fact correct then maybe Quickload should go in the trash.

My .02

Randy

[M-Tecs]

All the powder Manufacturers have ballistic labs with pressure testing equipment that is used and calibrated daily.

Agreed. It's difficult to argue with actual testing.

[44MAG#1]

The newest Hornady manual list for ENFORCER AND the 500 gr 33.1 gr as max at 1300 fps at 2.065" OAL
They list for 1680 at 44 gr at the same length.
Lyman's newest manual list for 4100 max at 29 grains at the same OAL
They list for Enforcer 28 grain max at the OAL same.

As they say "oh well". What do you do now?

[35remington]

Question because I have not tried it.

Is it possible to successfully seat a bullet given 126-140 percent loading density? Given the data, that implies it can, it’s safety otherwise notwithstanding. But I do wonder. Much depends upon the powder used and its compressibility.

[John Ross]

It's not that I haven't considered these things.

The real sticking point is that short OAL that they use, and it's printed right there in their data. I haven't seen .500 data with these charge levels and such meager OALs elsewhere.

I KNOW just by looking at their page that it's ridiculous to try to seat a 440 grain bullet over 47.5 grains of 1680 to a COAL of barely two inches.

But here's the kicker: According to Quickload, if you load to 2.300" OAL instead of 2.005", that 47.5 grain charge of 1680 goes from 140% density at over 180,000 PSI to 99% density and 47,000 PSI, and that is a load I have used myself with fine success.

But the company's data sheet says 2.005" OAL, not 2.300", and we're told to trust the manuals, and some guy who doesn't have as much experience as I do with the .500 is going to follow their directions to the letter instead of saying to himself "Wait a minute, that just doesn't look right..."

No luck so far in finding anyone at the company to talk to about this. Sending an email...

[obssd1958]

Well,
I happen to have on hand - Accurate 5744, Hornady 500gr. XTP FP bullets #50105, and brand new Hornady .500 S&W brass. I popped a used primer in the case, and measured out 39.9 grains of the 5744. Dropped the powder in the case and measured (approximately) the space left in the case from the top of the powder = .40 - .42 inches
If the Hornady bullet is seated in the case to an OAL of 2.070, then there is .565 inches of the bullet in the case. I'm not claiming anything about pressures for this particular load, but I would think that trying to compress a stick powder like 5744 that much, would not be a good thing! It also shows that the load density figures that John showed are probably pretty close.

Just my observations...



Don

[35remington]

Any answers to the question I posted above?

[44MAG#1]

Any remarks on the Hornady and Lyman data I posted above?

[John Ross]

The newest Hornady manual list for ENFORCER AND the 500 gr 33.1 gr as max at 1300 fps at 2.065" OAL
SNIP
Lyman's newest manual... list for Enforcer 28 grain max at the OAL same.

Hornady and Lyman show max loads that are FIVE GRAINS different with the same bullet, powder, and OAL?

This is getting weird...

[John Ross]

Any answers to the question I posted above?

Using powders that are known to behave when compressed, like BLC-2, I have achieved 120% loading density. However, such compression contributes to bullets jumping crimp under recoil.

I don't think 140% is possible, without the bullet coming back out of the case some before it gets to the crimp die.

[35remington]

I have more than a little experience with compressed loads, just not in this cartridge.

How about the powders posted in the data specific to the cartridge?

I am not suggesting the data is harmless, but if the load simply will not fit in the case, the highest predicted pressures are not achievable, and they also have some additional explaining to do beyond the primary issue of load safety. Like how could they get the powder to fit in the first place.

This is consonant with the question that begs to be asked, which is, “what were you guys thinking?”

[John Ross]

I have more than a little experience with compressed loads, just not in this cartridge.

How about the powders posted in the data specific to the cartridge?

I am not suggesting the data is harmless, but if the load simply will not fit in the case, the highest predicted pressures are not achievable, and they also have some additional explaining to do beyond the primary issue of load safety. Like how could they get the powder to fit in the first place.

This is consonant with the question that begs to be asked, which is, “what were you guys thinking?”

I do not yet have any experience with the first three of the powders listed but quite a lot with 1680. It is a ball powder like H110/296 or BLC-2. I have loaded it at density levels of around 110% but you have to watch for loads jumping crimp. I think 140% would be impossible as stated above.

My nagging suspicion in all of this is a bunch of typos made by a secretary that was hung over when she transcribed the figures her boss handed her...

[frank505]

I would trust western powders data having spent time in their lab and around their equipment. You could try talking to doug at the lab. Either he or Keith can answer your questions.