Date: 17 Feb 94  18:53:48
From: Ed Harris
To:   All
Subj: Surplus Powder Part I

The table which follows in Part IUI of this message identifies
Hodgdon powders and their Olin equivalents.  Before getting to
that, however, I want to explain the basic differences between
"Canister" and "Non-canister" powders.

For instance, current Hodgdon H110 is the same powder as 
Olin W-W 296, but in non-canister grade, so it does not
compare exactly to the canister Olin product.

"Canister-grade" powders sold for handloading are blended to
achieve a uniform charge-weight-pressure relationship so
that you can consistently use a given weight of charge for a
given bullet and have a safe load.  "Non-canister" powders
intended for factory loading don't have to be blended in the
same manner, because the charge weight is determined by
firing tests for charge establishment with each specific
lot.   The charge is adjusted in the loading machine to give
the required velocity and pressures.  This is why it is
dangerous to try to determine how much of a powder to load
by breaking down a few factory rounds and weighing them.   

Years ago I used WC665 in the .30 M1 carbine and in .357
Magnum using H110 data and it performed normally, though
giving velocities slightly less than H110, as it is a bit slower.
You could use H110 data and not get in any trouble.

WC820 is another noncanister powder sometimes compared to
H110, but some batches runb fast, and you have to stay well below
maximum loads until you know just what you've got.

Olin does not recommend 296 for reduced loads.  Period!
When I was at NRA they tested 18 grs. in a .308 with Saeco
180-gr. bullet, but the ignition-barrel-time tests were not
satisfactory.  I asked Dave Zaidan at Olin's St. Marks, FL
powder operation to test some loads after a rifle was blown
up at a cast bullet match I attended.  Some of the other
conditions of this particular incident were also suspect,
but if a powder manufacturer does not recommend their
propellant for reduced loads, I would be inclined to heed
their advice.

Hodgdon seems to have no such reservations about H110 for 
cast bullet loads, and I know many shooters who have done so
successfully.  Olin's caution is justified in today's
product liability climate, because they will not recommend
any load which doesn't perform satisfactorily under all test
conditions.  Their standard test routine includes elevated
(+125 degs. F.) and suppressed (-65 degs. F) temperatures,
as well as different powder orientations, powder forward,
powder back, powder leveled, etc.                  

Marginal ignition in reduced loads is aggrevated by use of a
primer which is lower powered than necessary to ignite the
charge.  This happens mostg often when a pistol primer is
used in a large case having more than 50 percent air space,
when the charge is not oriented against the primer.  Some of
the ASRFRA single-shot competitors use pistol primers in
order to avoid misfires in blackpower era rifles, such as
Ballards, which have weak hammer springs.  However, this can
causes ignition problems with powders having a heavy
deterrent coating, such as H110, when loaded at low loading
densities.

A fine-grakined powder like H110 has a small web size of the
base grain, and there is a very high percentage of deterrent
to propellant needed to obtain its slower burning rate,
compared to faster pistol powders like 231, which are of a
larger grain size.  Once you are aware of and consider this
factor, ignition problems should not then be surprising.  If
you get one of those crazy ignition situations, you are more
likely to ring the chamber, which I have had happen to me
using H110 in reduced loads in the .30-30 T/C Contender.

My advice is to use any powder exactly as recommended by the
manufacturer or supplier.  Don't experiment if you don't
know EXACTLY what you are doing!  When dealing with a
surplus powder it is a good idea to  do some comparisons
over the chronograph between the surplus powder and  a
similar canister powder, such as H110, over a range of
charge weights covering your region of interest, so you can
get an idea how they compare.  I usually fire 10-shot
strings at increments 2 grains apart in  a case such as the
.308 or .30-'06, starting at the suggested starting load for
the canister powder.  If the first two strings look OK, I go
to the next increment.  As I apoproach the velocity level I
want, or if the load may be approaching maximum I go to 1
gr. increments.

As you approach the desired velocity compute the energy in
foot lbs., and divide the striking energy by the powder
charge weight in grains.  This gives specific energy of the
charge in ft-lbs/per grain.  Do this for two charge weights
which bracket the velocity you want.  Then you can
interpolate and find what the specific energy should be for
the charge which will give you the desired velocity.  This
enables you to estimate an exact charge for a given velocity
with excellent accuracy.


--  CONTINUED NEXT MESSAGE  --



In Home Mix We Trust, Regards, Ed
 

--- msged 2.05
 * Origin: Home of Ed's Red (1:109/120.3006)


===============================================================================

Date: 17 Feb 94  18:57:30
From: Ed Harris
To:   All
Subj: Surplus Powder, Part II

     IDENTIFICATION OF SURPLUS HODGDON VS. MILITARY POWDERS
     Hodgdon Powder           Olin Powder
    
     HS-6                     540
     HS-7                     571
     H110                     296 (before '75 WC825 .30 Carb)
     BLC-2                    WC846 (Ball M80 7.62mm)
     H335                     WC844 (Ball M193 5.56mm)
     H380                     WC852 (Ball M2 Cal. .30)
     H414                     W-W 760 sold to Hodgdon
     H450                     785 (originally WC780)
     H870                     WC870 (20mm)
     HP38                     W-W 231 sold to Hodgdon
     Trap 100                 452AA sold to Hodgdon
     H322                     IMR8208M (M196 TRACER 5.56mm) 


                COMPOSITION OF IMR-TYPE POWDERS

The following table dates from 1976, and does not apply exactly
to current Canadian-production (Expro) IMR product.  Post 1976
Canadian made IMR powders are made from wood linters instead of
cotton linters. This results in somewhat lower nitration,
requiring a reduction of deterrent content to obtain equivalent
energy.  Therefore, these powders are somewhat faster burning and
require a charge reduction of about 5%, compared to older Dupont
products.  Handloaders are cautioned to use current powder
manufacturer's data with current product and not use old manuals!

The basic composition of DuPont IMR-type powders is 100% NC of
13.15% N content, to which are added 0.6%DPA and 1% K2SO4.  The
only exceptions are IMR4831, to which the DPA is 1.1% and IMR4895
which is 0.7% DPA.  IMR8208M contains an ethylene dimethacrylate
EDM deterrent.  All IMR-type powders differ essentially only in
their deterrent coating and granulation.

   IMR-POWDER GRANULATIONS AND COMPOSITIONS 
     Powder   Dia.   Perf.   Lgth.   Web   Coating  Density      
           (.65xdie)       (.93xcut)        (%)     (g/cc)
        
    4198      .027   .007   .085     .010   6 DNT   .85   
                                                    
    3031      .030   .007   .030     .0015  8 DNT   .89   
                                                    
    4064      .032   .007   .085     .0128  9 DNT   .90   
                                                    
    4320      .034   .007   .042     .014   8 DNT   .92   
                                                    
    4350      .039   .008   .085     .016   5 DNT   .925  
                                                    
    4676      .034   .007   .058     .013   7 DNT   .90   
                                                    
    4895      .033   .007   .058     .013   6 DNT   .90   
                                                    
    4831      .039   .008   .085     .016   8 DNT   .90   

     The length and outside diameter are not sufficient for
identification of the powder type.  The extrusion pin for cal.
.30 powders is .015" and inside shrinkage is approximately 55%. 
The granulation of a single perforated, extruded rifle powder is
expressed:                      
                       .049 x .015 x 1/11 
                                
in which the first group of figures represents the outside
diameter of the grain, the second group the diameter of the
perforation, and the third the length of the cut or the number of
grains per inch, when all dimensions are expressed  in inches.
The web thickness of a single-perforated grain is equal to 1/2 of
the difference between the outside diameter and the diameter of
the perforation.  A 1.0% decrease in web or 0.1% increase in
total volatile content (TV) will increase burning rate by 1%.  A
change in TV has ten times as much effect upon burning rate as a
corresponding change in web thickness.

The ballistic effect of a change in powder coating varies with
the basic composition, the granulation and the cartridge in which
the powder is used.  A rough approximation is 0.8 grain in charge
for cal. .30, and about four grains weight in charge for cal. .50
per one percent change in DNT coating, which is approximately
equivalent to 40 f.p.s. or 2000 p.s.i. (Cu). Reference powders
are used  to evaluate the suitability for acceptance of an
unknown powder lot or ammunition lot.  

Selection of a "reference lot" is based upon acceptable chemical
and physical characteristics and also depends upon satisfactory
ballistic performance in the cartridges for which it is intended.
Care is taken to protect and maintain the proper content of
moisture and volatiles as nearly constant as possible throughout
its existance as a reference lot.  This is done by keeping it in
airtight canisters during either bulk or sub-quantity storage.  
         
Assessments of reference powders are made in five pressure gages
which have been inspected to confirm normal dimensions for the
type of proof test weapon involved, and for which there is from
100 to 300 rounds of previous history, giving normal performance 
with reference ammunition. 
            
Charge establishment is fired in one gage equipped with a long
piston, using calibration components of the appropriate type,
hand assembled at the time of testing, so that the average
velocity of a 20-round series falls within the tolerance
permitted, preferably near the median velocity specified for the
ammunition type under test.  Each of the remaining four gages is
fired in the same manner, using the charge as established in the
first barrel.  If any gage fired with the long piston deviates
from the average of all five gages by more than +/- 20 f.p.s., it
is discarded, and another gage is selected in its place.  If the
average velocity of all five gages at the completion of the test
fails to come within the velocity tolerance permitted for the
type of ammunition, the charge weight is re-established in a
difference gage and the tests repeated.

After the charge weight has been established, and the established
charge has been fired in each gage with the long (velocity)
piston, a 20-round series is fired in each gage with the short
(pressure) piston, measuring velocity and pressure concurrently. 
If the average pressure of all five gages falls to fall within
the pressure tolerance permitted, the charge is re-established in
a different gage and the tests repeated.

The procedure described is repeated twice more upon succeeding
days, except that the charge established is first fired in the
gage with long piston, then the long piston is removed and
simultaneous pressure and velocity tests are completed on that
gage before proceeding to the next one.  With the possible
exception of the first long piston charge establishment, the long
piston and short piston firings in any single gage are to be
completed the same day.

At the completion of testing the average velocity of a 15 round
velocity series and a series of 15 rounds for pressure, with
velocities being measured concurrently, are distributed to the
using facilities as proposed assesment valiues, provided these
results are in conformance to the specification tolerances for
ammunition undergoing test.  If the averages fail to conform to
specifications, or if the uniformity or reproducibility of the
tests between series is poor, the entire assessment procedure is
repeated. 

Simulated assessment tests are made by each facility involved in
the manufacture of powder or ammunition type, upon receipt of the
proposed assessment.  Procedure for conducting simulated
assessment tests is the same as that described for assessment,
except the charge weight established at the master assessing
station is used for the entire simulated assessment series.



In Home Mix We Trust, Regards, Ed
       


--- msged 2.05
 * Origin: Home of Ed's Red (1:109/120.3006)

