4198 powders

[Scibaer]

 i see that the IMR 4198 and the H 4198 powders are listed right next to each other on the burn rate chart ( in the Lyman manual )...
but, are never next to each other in a load receipt.  so, that means that they must produce similar pressures for any given load ( right, no ? ) ..
i know they are not interchangeable, but how similar are they, or are they not, why.. why not ?
glenn

[LaOtto222]

They are similar - but not the same. When you are talking gun powder even one lot to the next lot can have different burn rates - slightly, but different. W296 and H110 are supposed to be exactly the same powders. Some load manuals list the same powder charges for both, some list the H110 with heavier charges for the same velocity and still other list the W296 as higher. The best policy when switching powders that are similar or even the same with a different lot is to start low and work your way up. Never interchange your carefully worked up load with another powder, even when they are almost the same or even the same burn rate. It is also prudent to do some work up even when using the same powder with a new lot. Some powders are notoriously bad about being different from one lot to the next and some do better. H322 and VV N133 are two popular powders with the bench rest crowd in the 6mm PPC because not only do they shoot well, they are some of the more consistent powders from one lot to the next. Good Luck and Good Shooting

[Catfish]

As 222 said, the same powder can vary from lot to lot. That said, they are so close that if you start with the starting load and work up watching for presure signs, you can use starting data form eather.

[Scibaer]

ok, well armed with that information i'll load up some rounds at starting levels and see how things go.
i will be extra careful about the grains i use, exchanging the H4198 for the called for IMR 4198.

question, the heavier the bullet the slower burning powder used and the heavier the bullet the more powder used, respecting the burn rate of said powder...
 is that about right ?
glenn

[blpenn66502]

Its just best to use the online Hodgdon reloading manual for what you are reloading  http://data.hodgdon.com/main_menu.asp  versus using a general rule of thumb of slower for heavier.

WRT your earlier questions, I'll go out on a limb and say that burn rates aren't good for anything other than creating a list that people expect to find in reloading manuals.  The nice thing about using Hodgdon's online load data is that often they show pressures for both starting and maximum loads.  I would guess that in load manuals they separate them to keep someone from inadvertently using the wrong data.  

The burn rate for a powder can be considerably altered by a number of factors; case size, expansion ration, bullet weight, etc. so the ranking in a burn rate chart is never a reliable method to determine interchangeability, estimate safe pressure or loads.
 
WRT the 4198 type powder similarity:  Similar pressures for a given load, in the same cartridge - NO.  Similar appearance, no, H4198 grains are shorter (can fit more in a case).  Similar accuracy - no reliable way to distinguish.  Same manufacturer, nope Canada for IMR and Australia for Hodgdon.  Names similar and same distributor, yes.  Why aren't they really similar, 'cause they are different.

[BBF]

question, the heavier the bullet the slower burning powder used and the heavier the bullet the more powder used, respecting the burn rate of said powder...
 is that about right ?
glenn
[/quote]

I am not sure I understand fully what you mean. The first part of your comment in regards to heavier bullets require slower powder( a general situation) I agree. Using more powder the heavier a bullet gets is NOT correct. You would be using less not more of the same powder. In some cartridges it may require three different powders to get the most velocity for the range of bullet weights available.

[Scibaer]

thanks for the link.  it does show both loads for the IMR 4198 and the H4198 with the pressure data.
that answers my questions for what i want to do.
glenn

[Scibaer]

BBF,
right i miss typed the second part of my question. i was primarly interested in relative burn rates and pressures for a given bullet weight.
i did mean to say less powder, respectively.
glenn

[BBF]

  Good, we are on the same page with that.
Forty some years ago when I started to reload I thought their was a misprint in the manual when it showed less powder for a heavier bullet. I figured the heavy bullet required more "work" to push out of the barrel which means more powder

The next thing I didn't understand how those reloading types figured I was going to count out 32.5 grains of  that little bitty pieces of powder without losing my mind. Suffice to say I got it right and survived,more luck then smarts I can tell you.

[Scibaer]

  yep. i am making up some match grade rounds, brass all same exact weight and volume, headstamp, bullets same length and weight. powder same weight and volume. primers same weight.. you get the idea. then tests and more tests. strickly for my own education and usage. the two calibers i'm working with are the .30-30 and .243, both winchester
glenn

[Blowtorch53]

Hi Scibaer,

IMR 4198 is a great powder.  I like "log" powder because I use an automatic scale.  IMHO you should never consider using one brand of powder with another powders data no matter what the burning rate might be.  I would never use H110 with W296 data, although people say they are the same.  This stuff creates a small explosion in our guns with pressures in excess of 50,000 psi in some instances.  Especially the latter magnum powders I mentioned.  The .45-70 has a lot of air space left in the case after charging, in some loads, and it could become like the mysterious .38 Special load that blows the gun to pieces with a small amount of Bullseye if I don't follow the instructions exactly.  I use only the correct data listed in the load tables for the particular powder listed.  This should be modern data and not from the first edition of the Speer manual.  Some of the reduction in the new data is from lawyers but a lot of it is because we now can measure pressures accurately.  For $25 worth of powder, I don't want to blow up a nice gun and lose fingers or eyes.  Not a lecture but just my opinion for all your great guys.  Thanks!!

BT53

[Scibaer]

torch,
you are right, those are great words of widsom, for all of us to live long lives by.
thanks for the reminder
glenn

[Blowtorch53]

Glenn,

BTW that "Buffalo" rifle is gorgeous!  I have a Marlin 1895 .45-70 that is a real shooter.  I WANT a Ruger #3 .45-70.  It is a great cartridge.

Thanks,

BT

[Scibaer]

BT,
 thanks it really revolved around the heavier monte carlo stock to absorb some recoil, but it does shoot real well. since that pic i got some brass furniture brads and decorated the stock like the fur trappers of old did.
the ruger #3 or #1 as what i hope to have one day myself and i can only dream of a sharps... 45-70's of course
i bet that marlin is a sweet rifle too. i have a 1949 marlin 30-30 rc thats shoots like a dream i wish it was a 45-70 though.
glenn