Who do you trust?

jbmoose

The more I study reloading the more confused I get.[:(] When looking at the various load tables out there, no one seems to agree on what the maximum load is. For example, four different, reliable sources all disagree as to what the max load for 308 Win with a 155 grain bullet using IMR 4895 should be.[V] The following are the max loads and velocity from people who should know: Hornady 44.7gr.-2,700 fps, Lee 46.0gr.-2,873 fps, Hodgdon 47.5gr.-2,897 fps, Sierra 43.7gr.-2,800 fps. This is a 3.8gr. range for a max load. Hodgdon's starting load, 43.5gr-2,664 fps, is almost the same as Sierra's maximum load.

Can anyone explain this to me and who do you trust?

swearengine

You can trust all of them.

There is more to loading a round than just filling the case with powder. What brand of case were all those different manuals using? Internal dimensions wil vary between differing brands of cases; and even between different lots of the same brand, although that will be less of a variance. What type of primer is each manual using? When you are studying these manuals, you need to use components that mimic what the manual states and then start at the bottom of the scale as maybe the chamber dimensions of your rifle will be such that your load will be overpressure.

If you read your manual first, understand what the author is saying, and then load your cases, you will have a much more rewarding experience.

HandLoad

Or, put another way, you can trust them as to their statements, but what they each are saying is that IN THEIR GUNS, they found those loads to be safe.

Load Books are NOT "Cookbooks", where it is virtually Guaranteed that if you follow their recipe, you will get the exact same results. They are GUIDE books, to help you minimize the danger, and get you near a desired result. You have to generate the Knowledge Base for your choices.

You are loading for Your Gun, Your Elevation, Your Temperatures, Your Powder lot, Your Case capacity, Your Primers, Your Bullets, Your Lube, and so on...

So, start at a safe level, and carefully change ONE thing at a time, slowly accumulate all you need to know about what changes make the desired results. No one here can speak for your choices but you. No One Here can assure your safety. Just You. You are playing with Explosives. Play Safe.

Hawk Carse

I do a bit of target shooting, as I expect you will with that combination. Applying logic, field reports, and experiece; I will say that the Sierra data shows the lightest loads and is roundly considered very mild, conservative, even timid.
The Hodgdon data shows the heaviest loads, and I do not care to use their maxima. Some do, but they are paying in brass life and gun stress for a few extra feet per second.
I suspect the Lee data is some of the last derived before Hodgdon secured distribution rights to IMR powder and think that it may well represent a working maximum.

wsm 325

i wondered the same thing. i was told its all in the bullett composition of different manufactures. when i load hornady bullets go off hornady book. same with nosler.

sandwarrior

jbmoose,

quote:Originally posted by HandLoad
Or, put another way, you can trust them as to their statements, but what they each are saying is that IN THEIR GUNS, they found those loads to be safe.

Load Books are NOT "Cookbooks", where it is virtually Guaranteed that if you follow their recipe, you will get the exact same results. They are GUIDE books, to help you minimize the danger, and get you near a desired result. You have to generate the Knowledge Base for your choices.

You are loading for Your Gun, Your Elevation, Your Temperatures, Your Powder lot, Your Case capacity, Your Primers, Your Bullets, Your Lube, and so on...

So, start at a safe level, and carefully change ONE thing at a time, slowly accumulate all you need to know about what changes make the desired results. No one here can speak for your choices but you. No One Here can assure your safety. Just You. You are playing with Explosives. Play Safe.


I really like what he's saying here. I will add that what you need to trust is the starting load. In every manual you come across they say "START LOW AND WORK UP". There is a reason for that. You can start to see pressure signs before they do damage to either your rifle ...or you! Work up in regular small increments. Sometimes when you get a new powder you may want to work up more slowly. Each powder and bullet combination are different in your rifle. You will also see along the way where the best accuracy nodes are.

I read something a while back, "The Progession of a Reloader" {author unk.}(an excerpt as I don't know who wrote it and it's not complete)

I got into reloading to save money. The cost of store bought shells was just too high.
Immediately, I found I could load bullets hotter than what loaded shells at the store got that I could buy.
It was fun because I could load for some rifles that nobody could shoot as flat as me.
After a couple burnt out barrels and a lot of ruined brass from one or two time hot-loads, I realized I wasn't saving any money.
When I backed down on my loads a bit, I found that not only was I saving money, I found where my newly barreled rifle shoots the best.
Now I save money and get excellent accuracy.

jonk

Add to that that powder lots vary from lot to lot. The lot they used to make their data could be a tad slower/faster than current.

I'd use the lowest data for my start point and depending on the gun, feel free to work up to the highest max, but only in .5 gr increments and watching for pressure; and over a chronograph. Otherwise I'd take the mid set of data as the max.

just me personally.

Rocky Raab

To echo what has been said, the loads you find in the books are accurately reported. So each, in its way, is true and correct.

The differences are easy to understand, really. Every manual is produced by a different company, using different components, in different test guns, in different weather, in different places, at different times, using different test equipment, by different people, analyzed with different priorities and possibly under different rules.

Would anyone expect the reported results to be identical?

My own rules, developed over a half-century of reloading:

Use the bullet maker's data as primary, because bullet shape, materials and construction can make the largest difference in pressure results.

Check with the powder maker's data to be sure there are no gross mistakes in the bullet data (it DOES happen!)

Verify with an independent tester's data (Lyman is the best) to be absolutely sure. In the event of large discrepancies among ANY of those sources, contact the manufacturer whose data is "off" to learn why.

Use PERCENT of the expected maximum charge to set your test load powder increments, rather than any fixed, arbitrary amount like a half grain. Percentage increments work no matter how large or small the charge weight. I use 90% of maximum as my Start load, and 2% of the maximum as my charge increments. That gives me five sets of test loads between Start to Maximum. Once I find a accurate load, I "tweak" it at 1% either side. Rounding off amounts slightly for convenience is fine.

jbmoose

quote:Originally posted by HandLoad

Load Books are NOT "Cookbooks", where it is virtually Guaranteed that if you follow their recipe, you will get the exact same results. They are GUIDE books, to help you minimize the danger, and get you near a desired result. You have to generate the Knowledge Base for your choices.

I never thought of it that way and it makes sense. I've been reloading since last December, so I know there is a lot to learn. Are all of you suggesting that I load and test fire 5 to 10 rounds of a particular batch before making more? When I do this, what am I looking for? I don't have a chronograph yet so I can't check velocity. Do I strap my gun into a Ledsled and measure groupings? What am I comparing the results against, commercial loads and which one?

Using the cookbook analogy, I'm using recipes and I'm not even sure what the cake is supposed to taste like! I've read the Hornady book and have started on the Lee book. Is there a better resource out there? I have not done competition shoots yet but I would like a better comfort level knowing if I'm doing it right or not.

Rocky Raab

In the absence of a chronograph, the only thing you can use as a result is the group size. That's not much of a handicap, by the way. Accuracy is MUCH more important than speed. You can calculate or compensate for bullet drop, but you cannot anticipate where the next poor grouping bullet will go.

Shoot five shots of test loads. If one or more loads shoot a small group, shoot five more of that combo with no changes. Four or five small groups with a load start to become proof of a good one. Remember that one small group can be a random event, but a large group is never one. To REALLY prove a load, shoot multiple groups at longer range.

Do buy the Lyman manual as your next info source. It is consistently accurate, and the "how-to" sections are excellent.

JustC

the major differences in their data come from their barrels they use. Many use aftermarket barrels with tight match grade chambers and higher land heights, as well as varying their twist rates. Some use factory barrels. Primer difference and brass difference further add to the equation.

Also, their lot-to-lot burn rate differences in identical powders which have been purchased by different companies at different times will affect the data.

Also, they don't specify the amount of neck tension they used, the thickness of the brass, wether they used a crimp, etc etc etc.