I was just heading to the bench to make some 180 grain accubond loads for my .300 H&H because the weather is nice enough to shoot tomorrow!

I go to Hodgdon's website to see that 73.5 grains of IMR-4831 is a max load and yields 3,035 FPS

also IMR-4350 is a max load at 69 grains and yields 2,990 FPS

Both of these loads are 54,000 CUP....and that's a strong load for sure.....

But then I double check my Hornady manual as a second opinion reference....and holy crap winneta!

Max load of IMR-4350 is 59.7 and yields 2,700 FPS
and max load of IMR-4831 is 63.5 grains and yields 2,800 FPS
These loads are a full 10 grains different!

So I'll look at Nosler's website to see that they list IMR-4831 as max at 66.0 grains and yields 2,940 FPS

They do not list IMR-4350

Based on this I'll start my loads at 60.0 grains of IMR-4831 and work up to no more than 66 grains and re-evaluate then.

It's clear that the Accubond is so long that it consumes case capacity and raises pressure somewhat.....But 10 grains???

I post this simply to say.....the value of checking several sources is sound! There was a time years ago when I might have started working up at 68 grains or so!

An here I thought someone was of the Hindu faith !.

I have my Nosler #6 reloading guide open as I type.
It lists 65gr of IMR4350 as maximum with the 180gr Accubond & a MV of 3010fps.
The Hodgdon site does generally list loads somewhat higher than the maximums given by bullet manufacturers & I've run their .243 & .270 loads without issue.
Note that the Hodgdon data is for the Sierra SPBT which is a LOT different to the Accubond.

Maybe the bullet makers loads are intended to be lawyer proof.

PS Just looked at the Hodgdon site data & I see 73gr for 53,500CUP for IMR4831.

I dont have the newest hornady manual.But the last one can not be trusted unless your wanting reduced loads!!
2300 fps 55 gr vmax 20" AR with MAX loads.
I nomally use the lee or speer data,but I thought I would give the hornady book a try. Not again!!I like their bullets.But their data was written by some lawyer I think!!

Hey Vapo, You could always get "the Doughnut Eater" to run some Non-Calibrated, Guessed at Dimension, Fudge Factored - Haphazard SGS fiascos for you.

quote:

Originally posted by Hot Core:
Hey Vapo, You could always get "the Doughnut Eater" to run some Non-Calibrated, Guessed at Dimension, Fudge Factored - Haphazard SGS fiascos for you.

LOL.....actually I have found council with quickload and find it to be very valuable information.....and no...it's not a pressure gauge but it sure helps take some of the guess work out of finding a starting point!

quote:

Originally posted by ty_falcon:
I dont have the newest hornady manual.But the last one can not be trusted unless your wanting reduced loads!!

Looking @ the data I tend to think you are right. My favorite manual is so simply because I find the data to be the most credible, your C.U.P. may vary. And I show 66 to 70 gns of IMR 4831 with a 180 gn pill.

Im thinking your Hornady manual was designed for lawyers.. That said, the Hodgon variation may be just a bit hot..

I never imagined you as an extremist Vapo..

quote:

Originally posted by Wstrnhuntr:
I never imagined you as an extremist Vapo..

When it comes to preserving my eyes and hands.....I most definitely am!

quote:

Originally posted by vapodog:

quote:

Originally posted by Wstrnhuntr:
I never imagined you as an extremist Vapo..

When it comes to preserving my eyes and hands.....I most definitely am!

You got that right! No extra 50 fps is worth a severed skull..

Vapodog brings up a very good point. Check several sources of information before you start loading. I've been loading for 45 years and there have been several similar discrepancies between different loading manuals over the years. Something I have found to be very useful over the years is keeping careful records of different loads I have tried for individual rifles. Its easy to keep a hardcopy record or put it in a spreadsheet. I keep track of bullet weight, bullet manufacture, case,primer, type of powder & weight in grs used. Things like COL,velocity and group sizes etc are kept in a comments column on the right side .The model & serial # of the rifle is also recorded on each page. So when I want to try a particular bullet/ powder combination I check several loading mannuals like everyone should and I check my own manual that I have created for that firearm. As vapodog has pointed out ,I like the idea of keeping both eyes and all my fingers in good working condition.

quote:

Originally posted by Wstrnhuntr:

quote:

Originally posted by vapodog:

quote:

Originally posted by Wstrnhuntr:
I never imagined you as an extremist Vapo..

When it comes to preserving my eyes and hands.....I most definitely am!

You got that right! No extra 50 fps is worth a severed skull..

You could always buy a RUM if you want more velocity

I agree with the idea of checking several sources for loading data...and when I describe my methodology you are going to call me totally insane but blame it on my scientific background.

When getting ready to load a new combination I have a Excel spreadsheet that I use to collect data for every source that I have. I have purchased nearly every loading manual in print (not VihtaVuori as of yet) for a number of years so I end up with a large data set. I will choose 2-3 powders for a bullet weight based on some general reference like Ken Waters articles and collect the data across all the loading manuals. I will include a few Internet resources (though always with a skeptical eye) that I have known to be reliable in the past. I run a few stats on the list of charges like mean, median and mode but more importantly I run a Grubb's outlier analysis (roughly based on Nalimov's outlier method I think, see Grubb's Test) to see if any of the charges are well away from all the others. That is often interesting and eye opening...for example I have often found Steve's Reloading page data to be hot. I then decide on a maximum charge usually excluding the outliers and work up from there usually 15% or so lower depending on cartridge. While going through the loading I keep in mind bullet specific issues like loading for the older Barnes X (non TSX) bullets which I have a stash of, often cannot go to the maximum I have chosen before exhibiting excessive pressure signs with all the normal methods of detection. I also have developed some pattern knowledge of the manuals themselves for example it is generally accepted Swift data is conservative ( confirmed to me by Bill Hober). In 30 years of loading nearly 30 cartridges I have only once locked up an action no doubt due to the 101 degree temperature that day and my forgetting to put the ammo for test out of the sun.
I said you were going to call me crazy!
YMMV
Paul

Don't know if this relates but 68 gr of IMR 4350 with Hornady 180 gr sp in my pre-64 M70 26" bbl clocks 3034 fps, using standard WLR primers.
C.G.B.

I have this really neat, not so new invention. It's called a three ring binder. And a pencil. You can add or take away sheets as the need arises. I also have a hole punch. And I make my targets 8"x11". Then I make three punche holes down the side of the target and put it in the three ring binder. Any commentary regarding weather/wind conditions are logged onto the face of the target. The very first sheet in the binder has the rifle model/serial #/bedding info/etc. On the spine of the binder, I have which rifle it is.
I started doing this way before a computer was the center of the household and before they invented portable computers so you could take a shit without interrupting your cyberspace experience.
My system works even for those of us who are kinda computer stupid.