i really need to have this explained to me


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mypps
July 22, 2009, 12:29 AM
okay, so here we go. i recently started to reload, 9mm for now, but more later. anyway, my question has to do with the measuring of powder charges. i have looked at several books and each one calls out for different amounts for the same load. i am using winchester 115 gr. fmj bullets, imr 700x powder and mostly winchester brass. depending on where i look, i see different measures. i am only making target rounds and don't need to go crazy with it. is there some rhyme or reason to the varrying numbers? who should i believe? i still have all 10 digits and would like to keep it that way. thanks.:confused:

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ar10
July 22, 2009, 12:35 AM
Pick one or two, then start at the lowest published load, (I don't think they're that much different). then work up the load. I use the Hornady, Speer, and Nostler manuals and all three vary a little.

paradox998
July 22, 2009, 12:38 AM
I have found the same problem. Based on my somewhat limited experience, I usually go with a lower end load to start with and work up. Also, I give a little more weight to the values supplied by the powder manufacturer.

liljohn
July 22, 2009, 12:58 AM
The differences in load data between loading manuals exists because there are variations in all components involved in measuring pressures. Some of the variables are:

case thickness (affecting volume and neck tension)
bullet shank length (affecting volume and neck tension)
bullet mass
Bullet diameter
powder burn rate (it will vary by lot)
cartridge OAL
pressure barrel dimensions (chamber, bullet, throat, etc)
pressure measuring methodology
ambient temperature and humidity
elevation (affecting air density)

The effect any one of these variables might be slight, but all together could result in a variation of 10% or more between compiled results of two independent test cases.

mypps
July 22, 2009, 01:14 AM
i've looked at the different loads. one source says 3.3 to 3.7 max, and another says 3.3 to 5.0 max. i made a few rounds at 4.0 gr. using the latter source of info. i'd hate to have to take them apart. but if i must i must.

Steve C
July 22, 2009, 01:19 AM
i have looked at several books and each one calls out for different amounts for the same load.

Manuals and on line data come from 2 different sources, the companies that manufacture or market powder and the companies that manufacture bullets. The data from the bullet manufacturer is developed using their bullets while the data from the powder manufacturers are a bit more generic.

All the data sources tell you the maximum charge they suggest and you need to be knowledgeable enough to use proper load development and reduce that maximum load by 10% for your start load and work up, testing each incremental charge increase, to no more than the maximum load while looking for potential over pressure signs and finding the "sweet spot" that shoots the best in your pistol or rifle. Stop and back your load off a bit if pressure signs appear. Other manuals will print a start load, essentially doing the math for you.

By working the load up from the start load you will maintain a safety margin despite using different components than the data was developed with.

This is data from the Hodgdons on line data. While your 4.0gr load is a bit warm it should be fine. I've looked through several data sources, old and new, and none of them listed a 700X load at 5.0grs, are you sure you where not reading 800X or perhaps a 90gr bullet?

rg1
July 22, 2009, 01:49 AM
Loading 9MM with it's small capacity case depends a lot on your bullet seating depth too. If you seat your Win 115 fmj's to a long overall length pressure will be less than if you seat them shorter. Here's some data from Midway's LoadMap series. They seated the bullets very long for 115 grain fmj's. They seated to 1.165" with the Win 115fmj, used Win sp primers and Remington cases. With IMR 700X powder they started at:
3.3--898fps--19500 psi
3.5--941fps--21600 psi
3.7--984fps--23800 psi
3.9--1027---25900 psi
4.1--1070---28100 psi
4.3--1113--30200 psi
Midways 9MM LoadMap does warn that seating them shorter than their tested length increases pressure. I listed the loads just to show the pressure increases with increases in powder. That's what I like about Midway's Loadmap series of 4 books. They printed them in .44Mag, 45ACP, 357Mag, and 9MM. Guess the profit margin wasn't there as these are the only ones they made and they are not available anymore. They tested about 10 different powders for each bullet and tested a lot of different companies bullets. For instance with 9MM 115 grain bullets they tested 17 different 115 grain bullets. You can get a comparison of different bullets with the same powder charge and which creates more pressure. Just for your info. With the 1.165" oal and the above components they said Caution going above 4.3 grains of 700X powder and 4.5 as a Maximum load to not go over. Now if you load them shorter then pressure will increase.

Marlin 45 carbine
July 22, 2009, 10:07 AM
I've noticed variations in powder data will vary due to test barrel length also, from maual to manual that is. ever so slightly maybe but there may be.

ar10
July 22, 2009, 10:09 AM
The other issue is each of the manufacturers use different weapons when they test the loads. And not all guns are created equal. A good example is the .308 that I load all the time. Mine are for the AR10B while they, (manufacturer) is using a bolt gun. To complicate matters they all test fire different bolt guns. I know I cannot use their exact load info for a semi auto.

mypps
July 22, 2009, 10:31 AM
and none of them listed a 700X load at 5.0grs, are you sure you where not reading 800X or perhaps a 90gr bullet?

this was in a book from sierra that i found at cabelas. well more of a binder than a book. that book lists 5.0 gr. as the max recommended load. and i'm using fmj not gdhp. i've been setting the rounds all at 1.160", the same as the WWB that i usually shoot with. so to be safe, should i pull these rounds and redo them with less powder? i'm using a walther pps, which isn't really recommended for use with +p rounds anyways, making me question my measures.

loadedround
July 22, 2009, 10:42 AM
AR10 has basically nailed it. Even a new out of box pistol or rifle of the same make and caliber will show different signs of pressure with a given load. Majority of all new firearms are mass produced , and therefore the wear on the factory's chamber and/or barrel reamers will affect that firearm's maximum chamber PSI, depending on how worn the reamer is, and hence it's maximum load capilbilities. Speer did a study on this a few years ago and published in one of their loading manuals under the title "Why Ballisticians Get Gray". :)

ranger335v
July 22, 2009, 02:37 PM
"The other issue is each of the manufacturers use different weapons when they test the loads."

And there is your answer. No component change we can make to a book load is as important as that one.

showmebob
July 22, 2009, 05:01 PM
I load Berrys RNDS 115 gr with 4.2 gr of 700X and still get 2% FTE. Any less of a charge and the FTE rate goes up. One caution with 700X. It doesn't measure well at all in my powder measure (+/- .2 grains) so be very careful to avoid an overcharge if you are loading near maximum.

myg30
July 22, 2009, 07:33 PM
Working "UP" a load means start at the low end and go up from that.
As others have said, your sweet spot can be at the low end of the charge.
My .40 cal loads are at the low end and duplicate factory ammo and I didnt need to re-adjust my red dot site. POI is the same ! That was my goal.
Why waste more powder ?

Be safe, Mike

mypps
August 11, 2009, 10:54 AM
well, i've been trying different loads, working up from the low end and am now almost at the max load i found at IMR's website(3.7 gr.). the gun will fire, but most times it won't strip a round out of the mag. works fine with my store bought target stuff, but not my 3.6 gr. reloads. could that extra 0.1 make the difference? sometimes the round wil chamber, sometimes it comes part way out of the mag and jams. this never happens with the store stuff, so i can rule out the gun. i'm gonna go by the chart someone above posted and try 4.0 gr. and see where i am. thats in the middle of the charts range. maybe i'll do some at 3.8 gr. as well.

lykoris
August 11, 2009, 11:05 AM
sounds like it is too light a load.

I can look at my manuals and tell you what each one says given what you are using

metallic cartridge reloading - 3rd edit

distinction being it's a 115 grain JHP rather than your 115 FMJ bullet

gives for IMR700-X a starting load of 4.0 grains and a high of 4.5 grains

loadedround
August 11, 2009, 11:09 AM
MYPPS:
FYI, the current Speer #14 manual shows 4 gr of 700X powder with a 115 gr jacketed bullet 4.0 gr as the STARTING LOAD. With this information, I woould not hesitate shooting your already loaded ammo, but would be watching for obvious pressure signs. :)

lykoris
August 11, 2009, 11:09 AM
Speer 14th edition gives for a

115grain TMJ RN bullet and 700-X(I don't know this powder but presume they mean IMR700-X)

a starting load of 4.0 and a max of 4.4

COAL of 1.135"

lykoris
August 11, 2009, 11:10 AM
loadedround beat me too it:-))

I will check the other manuals but it seems your 3.6grain loads are a bit on the light side

lykoris
August 11, 2009, 11:13 AM
Lyman 49th edit

for a 115grain JHP with an OAL of 1.09 gives

3.1 for a starting load and 4.5 as a max for "700X" - again I presume they mean IMR700-X

they seat it deeper 1.09 hence the lighter starting load

lykoris
August 11, 2009, 11:16 AM
Lee 2nd edit

115grain jacketed bullet

IMR 700X 4.2 to 4.7

with min. OAL of 1.110"

lykoris
August 11, 2009, 11:21 AM
Sierra 3rd edit

115FMJ COAL 1.100"

700X - 3.8 (starting load) to 5.0(Maximum load)

my Vihta manual only has their powders but it seems you are on the light side of things.

What is your COAL on the rounds you have made up with 3.6grains of 700x ?

lykoris
August 11, 2009, 11:26 AM
sometimes the round wil chamber, sometimes it comes part way out of the mag and jams.

I suggest you take the barrel out of your handgun and use it as a case gauge to test the rounds you have made before you bring them to the range.

mypps
August 11, 2009, 11:35 AM
i'm using winchester 115 gr. FMJ. i'll make up some at 4.0 and head to the range this week and give them a shot. so what book does everybody like for reloads? i've been meaning to get a book for home.

hydraulicman
August 11, 2009, 11:36 AM
different bullet profiles create different pressure. find a middle ground between your books

mypps
August 11, 2009, 11:44 AM
I suggest you take the barrel out of your handgun and use it as a case gauge to test the rounds you have made before you bring them to the range.
i actually have been doing this and none fit tight. i am alittle leary of the reloading thing and try to cover all my safety bases. if i remember right, i made the length the same as the winchester rounds i have, which are i think are 1.16"(don't quote me on that). thats within spec. for the lee dies i have.

lykoris
August 11, 2009, 11:52 AM
speer is good, I like the Lyman and Sierra ones too.

krs
August 11, 2009, 01:37 PM
mypps: this never happens with the store stuff, so i can rule out the gun.

No, it's not that simple, and it's not the load's fault necessarily.

Your pistol's recoil spring is chosen by the manufacturer to work best with one generic or universal load, most like what is generally available in boxed ammo.

If you chose to reload, and you chose a lighter load you will need to adjust the spring tension in your pistol' recoil spring so that the gun will cycle with the lighter cartridge energy.

So if you are varying your loads you need to vary your pistol correspondingly IF the new load cause the pistol to be unable to function normally.

If you were to chose to load much hotter than storebought ammo you would find that the pistol will work but will probably smack you somewhat harder. It needs a stronger spring to balance the function against the higher pressure or eventually something will break in the pistol.

It's why Wolff Spring Company exists and supplies springs of different rates for same guns.

mypps
August 11, 2009, 02:01 PM
my walther pps uses a 2-piece spring assembly that can't be taken apart. so i have to load the cartridge to function in the gun. not much choice in that. unless wolf has started making spring assemblies.

fireflyfather
August 11, 2009, 02:11 PM
Other considerations (I only skimmed, so might duplicate some earlier comments):

1. Year when the load data was published. Older manuals have listed different charges both because of changes to the powders manufactured, and because of lawyers/marketing.

2. Components can vary a lot. Not just which bullet they tested, but which brass, which primers, or even type of primers (magnum/regular).

Then you get into the fun of which LOTS of primers and powder they were using, what testing methodology, what their criteria were for max-loads (see lawyers above), etc.

Basically, if you just want plinking ammo, start at the BOTTOM, and work your way up until the loads are accurate and cause your weapon to cycle properly. You may even want to consider how cleanly the load burns, but that's more a question for someone who uses your powder in that caliber. As a general rule, you should always start with starting loads and work up, using a similar bullet type and OAL. It seems that you are doing this.

Shoney
August 11, 2009, 05:10 PM
Each manual will list the weapon used, barrel length, case mfg., primer, and so on. Take a closer look at the weapons/brass/primer/ et cetera
used in the data workups. They are probably very different, and also different from your weapon/brass/primer/ et cetera.

Combinations of factors can cause great variances in velocity/pressure. Here are a few factors:

Primer: amount of striking force on primer, strength, presence of powdered metal (Aluminum & others), brisance - a measure of the rapidity with which an explosive develops its maximum pressure
Barrel: length; tightness of bore; height of the lands; distance of bullet to lands; temperature of barrel;
Bullet: bearing surface of bullet, alloy of bullet; shape of bullet; diameter;
Brass: new/used elasticity; manufacturer, volume;
Powder: new, aged, old, batch powder was from;
Weather: ambient air temp., barometric pressure, humidity
Elevation: above sea level
Other: I am sure I have not listed all.

Now, mix and match them. Would you care to guestimate the number of possible combinations,

Bottom line - - - use the books as references, not gospels. Examine the data, select a low starting load, and work up loads slowly, watching for pressure signs. Your weapons max will probably vary from all other listed references. Thatís the fun/frustration of reloading.

Good Shooting!!!!!!

mypps
August 12, 2009, 01:11 AM
so what pressure signs are you refering to? cracks in the cartridge cases?

Shoney
August 12, 2009, 02:11 AM
Any good loading manual should have a section on pressure signs. Primers being flattened is usually mentioned as a good sign, but it isn't IMHO. Some primers are soft and flatten at low pressures; some are hard and don't flatten until you are over max.

With Bolt Rifles
The better signs I use durng a load work up are:
Leveling off or lowering of velocities with an increase in powder charge.
The bolt becomes sticky or hard to open. At this point you may see cratering of the primer, expansion of the case in the web, and shiny marks left by the extractor.

With Revolvers
Cases are hard to extract from the cylinders.

There are no reliable signs for pressure in the brass from semiauto pistols and rifles until after the max is exceeded. Excessive pressure that are moderatey over max usually show as damage to the weapon. Really excessive pressure usually give you a KB.

Good Shooting!

lordmorgul
August 12, 2009, 03:57 AM
I've had a very similar issue working up to a 'valid' load for my HK USP 40 and my brother's HK USP 40C. Our guns take a much hotter load to function than our friend's Glock. The starting loads I've found for both Win231 and Accur #2 with a 165gr plated FMJ do not function in the HK guns while they work fine in the Glock. It is important to find what works for yours, but get there carefully.

I like Lee's Modern Reloading, but I'm as new to this as you mypps.

ArchAngelCD
August 12, 2009, 05:13 AM
According to Hodgdon the charge range for a 115gr GDHP bullet using 700-X in a 9mm case is between 3.9gr and 4.2gr. A charge of 4.0gr should be a good starting point and possibly the charge you will keep using. I like to check with the powder company when developing a new load or when using a powder for the first time in a caliber. The Hodgdon Load Data Site (http://data.hodgdon.com/main_menu.asp) is very large and covers most calibers. They update their data often so it's current data. The Hodgdon site covers all Hodgdon, IMR and Winchester powders.

mypps
August 12, 2009, 10:25 PM
i have been using the info from the IMR site. same as the hodgdon site. i'm not using hollow points, but it seems that maybe 3.8 grains should fix my problems. i had a few rounds that fired and chambered the next round. i was hand measuring the i might have been off by .1 or so grains.

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