joeb33050
04-11-2008, 09:34 AM
POWDER POSITION SENSITIVITY TESTING
Does the position of the powder in the cartridge case affect muzzle velocity, (MV) and/or the standard deviation, (STDEV) of MV?
I had tested the sensitivity of a powder by testing for increased accuracy with a minimum sized Dacron wad tamped down on the powder; and concluded that, for example, SR4759 and Unique are position sensitive in the 45/70 and IMR4227 is not position sensitive in the 32/40 and 30/30.
The testing conditions were expanded when I realized that my definition and test conditions were not complete (or correct); this epiphany occured after a lot of testing.
TESTING CONDITIONS
POWDER FRONT-hold the rifle with cartridge chambered at ~ a 45 degree angle down and slap the side of the rifle three times, then put it carefully on the rest.
POWDER LEVEL-put the rifle with cartridge chambered on the rest and slap the side of the rifle ten times.
POWDER REAR-hold the rifle with cartridge chambered at ~ a 45 degree or greater angle up and slap the side of the rifle three times, then put it carefully on the rest.
DACRON WAD-I recommend cotton but use Dacron wads. I use as small a wad as possible, a teased wad about dime to penny size, tamped down on top of the powder with a pencil.
I try to chronograph a minimum of 15 of each condition, shooting at 100 yards over my PACT chronograph.
Il record all results on an EXCEL workbook called "POWDER POSITION SENSITIVITY" and a WORD summary, this is it, called " POWDER POSITION SENSITIVITY TESTING". (See the EXCEL workbook for all the information about the loads and results.)
These two files are and will be on http://sports.groups.yahoo.com/group/CB-BOOK/ in FILES,in ERRATA
AVERAGE VELOCITY
DATE CALIBER POWDER GRAINS POWDER FRONT POWDER LEVEL POWDER REAR DACRON WAD
2/6/2008 30/30 Unique 7.0 1,195 1214 1185
4/9/2008 30/30 Unique 7.0 1163 1175
2/20/2008 30/30 Unique 8.5 1346 1365 1378
4/9/2008 30/30 Unique 8.5 1337 1368
2/20/2008 30/30 Unique 10.0 1502 1519 1498
4/9/2008 30/30 Unique 10.0 1491 1478
2/27/2008 45/70 Unique 14.0 1195 1240
2/27/2008 45/70 SR4759 22.0 1128 1310
3/12/2008 30/30 IMR4227 14.5 1353 1347 1435
3/12/2008 30/30 IMR4227 14.5 1357 1357 1454 Rem 2 1/2
3/26/2008 30/30 IMR4227 14.5 1457
4/9/2008 30/30 IMR4227 14.5 1392 1451
3/26/2008 30/30 IMR4198 18.5 1614 1629 1650
STANDARD DEVIATION OF VELOCITY
DATE CALIBER POWDER GRAINS POWDER FRONT POWDER LEVEL POWDER REAR DACRON WAD
2/6/2008 30/30 Unique 7.0 28.1 39.3 14.3
4/9/2008 30/30 Unique 7.0 17.8 19.8
2/20/2008 30/30 Unique 8.5 16.1 18.8 29.5
4/9/2008 30/30 Unique 8.5 16.6 29.3
2/20/2008 30/30 Unique 10.0 28.8 22.3 19.5
4/9/2008 30/30 Unique 10.0 46.0 11.3
2/27/2008 45/70 Unique 14.0 28.0 15.8
2/27/2008 45/70 SR4759 22.0 35.5 31.8
3/12/2008 30/30 IMR4227 14.5 19.0 17.7 14.3
3/12/2008 30/30 IMR4227 14.5 30.4 25.5 22.7 Rem 2 1/2
3/26/2008 30/30 IMR4227 14.5 24.3
4/9/2008 30/30 IMR4227 14.5 26.1 20.6
3/26/2008 30/30 IMR4198 18.5 32.3 24.4 30.9
iT WOULD CERTAINLY HELP IF SOMEBODY COULD MAKE A word document print here. Anybody??
joe b.
Does the position of the powder in the cartridge case affect muzzle velocity, (MV) and/or the standard deviation, (STDEV) of MV?
I had tested the sensitivity of a powder by testing for increased accuracy with a minimum sized Dacron wad tamped down on the powder; and concluded that, for example, SR4759 and Unique are position sensitive in the 45/70 and IMR4227 is not position sensitive in the 32/40 and 30/30.
The testing conditions were expanded when I realized that my definition and test conditions were not complete (or correct); this epiphany occured after a lot of testing.
TESTING CONDITIONS
POWDER FRONT-hold the rifle with cartridge chambered at ~ a 45 degree angle down and slap the side of the rifle three times, then put it carefully on the rest.
POWDER LEVEL-put the rifle with cartridge chambered on the rest and slap the side of the rifle ten times.
POWDER REAR-hold the rifle with cartridge chambered at ~ a 45 degree or greater angle up and slap the side of the rifle three times, then put it carefully on the rest.
DACRON WAD-I recommend cotton but use Dacron wads. I use as small a wad as possible, a teased wad about dime to penny size, tamped down on top of the powder with a pencil.
I try to chronograph a minimum of 15 of each condition, shooting at 100 yards over my PACT chronograph.
Il record all results on an EXCEL workbook called "POWDER POSITION SENSITIVITY" and a WORD summary, this is it, called " POWDER POSITION SENSITIVITY TESTING". (See the EXCEL workbook for all the information about the loads and results.)
These two files are and will be on http://sports.groups.yahoo.com/group/CB-BOOK/ in FILES,in ERRATA
AVERAGE VELOCITY
DATE CALIBER POWDER GRAINS POWDER FRONT POWDER LEVEL POWDER REAR DACRON WAD
2/6/2008 30/30 Unique 7.0 1,195 1214 1185
4/9/2008 30/30 Unique 7.0 1163 1175
2/20/2008 30/30 Unique 8.5 1346 1365 1378
4/9/2008 30/30 Unique 8.5 1337 1368
2/20/2008 30/30 Unique 10.0 1502 1519 1498
4/9/2008 30/30 Unique 10.0 1491 1478
2/27/2008 45/70 Unique 14.0 1195 1240
2/27/2008 45/70 SR4759 22.0 1128 1310
3/12/2008 30/30 IMR4227 14.5 1353 1347 1435
3/12/2008 30/30 IMR4227 14.5 1357 1357 1454 Rem 2 1/2
3/26/2008 30/30 IMR4227 14.5 1457
4/9/2008 30/30 IMR4227 14.5 1392 1451
3/26/2008 30/30 IMR4198 18.5 1614 1629 1650
STANDARD DEVIATION OF VELOCITY
DATE CALIBER POWDER GRAINS POWDER FRONT POWDER LEVEL POWDER REAR DACRON WAD
2/6/2008 30/30 Unique 7.0 28.1 39.3 14.3
4/9/2008 30/30 Unique 7.0 17.8 19.8
2/20/2008 30/30 Unique 8.5 16.1 18.8 29.5
4/9/2008 30/30 Unique 8.5 16.6 29.3
2/20/2008 30/30 Unique 10.0 28.8 22.3 19.5
4/9/2008 30/30 Unique 10.0 46.0 11.3
2/27/2008 45/70 Unique 14.0 28.0 15.8
2/27/2008 45/70 SR4759 22.0 35.5 31.8
3/12/2008 30/30 IMR4227 14.5 19.0 17.7 14.3
3/12/2008 30/30 IMR4227 14.5 30.4 25.5 22.7 Rem 2 1/2
3/26/2008 30/30 IMR4227 14.5 24.3
4/9/2008 30/30 IMR4227 14.5 26.1 20.6
3/26/2008 30/30 IMR4198 18.5 32.3 24.4 30.9
iT WOULD CERTAINLY HELP IF SOMEBODY COULD MAKE A word document print here. Anybody??
joe b.