MUSTANG
03-06-2012, 04:41 PM
I have read numerous postings on Cast Boolits and other on line sites spanning several years where questions, postulations, fact, and fantasy have all been represented concerning the issue of individually weighing rifle bullets, and if it is worth the time to do so. I found many pearls of wisdom, some cast before swine so to speak; but no single succinct graphic demonstration concerning the issue. I thought it might be worthwhile to create exactly that demonstration; focused on what the "Average Cast Shooter" might expect and have available, not based on the "Master" Shooter/Caster/Machinist attempting to wring out the last fraction of an inch of accuracy.
To accomplish this I moved forward using the following control factors:
1. Select an "Everyman Rifle" for the test:
In this effort I pulled my first deer rifle from the back of the safe. I received it as a Christmas gift from my Dad back in 1972. It is a Western Field Model 870 in .308 caliber (This rifle is actually a Mossberg 800A, sold under license by Montgomery Ward as a "Western Field").
This rifle is topped off by a Bushnell "Scope Chief" 3X rifle scope.
2. Select an "Everyman Cast Bullet" for the test:
In this case I decided upon the Lee Precision C309-170-F Mold. This is a nominal 170 grain .309 mold. In my application with wheel weights it drops bullets at about 177 grains plus or minus depending on the batch of wheel weights.
Bullets for this test were derived from a casting session where about 250 bullets were cast. All were Water Quenched Wheel Weight Alloy.
3. Use an economical but accurate Scale:
I utilized a 1970's vintage RCBS 5-10 Balance Beam Scale. It has course measurements of 10 grains, with a fine adjustment threaded counter weight supporting measurement in 1/10th of a grain increments.
I have a small Frankford Arsenal digital scale; which I specifically decided Not To Use in this effort. It has a tendency to wander 3/10th to 5/10th a grain for up to 10 seconds when weighing bullets. Additionally, it has the same variation depending on where the bullet is placed o the scale. There is no apparent means of correcting the first variable condition; but I have drawn a set of "Cross Hairs" on the scale to identify the exact center to address the second condition. These variables were why I decided not to use a digital scale.
Bullets for the test were segregated into three groups. The first group was 177 grain (+) or (-) 0.2 grains. A second group of Heavy bullets were selected weighing about 178 grains (+) or (-) 0.3 grains. A third group of light bullets were selected weighing about 176 grains (+) or (-) 0.3 grains.
4. Use a common powder dispenser:
I utilized an RCBS Uniflow Powder Measure I purchased in the mid 1970s. The throw charge was adjusted to 13.7 grains of Unique powder as weighed by the RCBS 5-10 Balance scale. All loads were charged from the RCBS Powder dispenser. I made no further attempt to validate powder charges weights (e.g. I did NOT weigh each charge, but simply thre them through the Powder Dispenser).
5. Use a common set of Reloading Dies:
For this test I selected Lee's RGB (Really Great Buy) .308 dies.
6. Trim all Brass to same length:
For this test I used my Dillion RT1200 Trimmer. I would have preferred to keep with the "Everyman" theme by using my Lee .308 case trimmer, but my rechargeable drill died a few weeks ago and I have not replaced it. Years ago I would use the Lee Case Trimmer in a hand held mode for trimming; but due to hand fatigue and a touch of arthritis, I no longer do so.
7. Use a common Sizing/Lubrication method:
I utilized a Lyman 450 Lubrisizer with .311 sizing dies. For Lube, I selected Carnuba Red.
To accomplish this I moved forward using the following control factors:
1. Select an "Everyman Rifle" for the test:
In this effort I pulled my first deer rifle from the back of the safe. I received it as a Christmas gift from my Dad back in 1972. It is a Western Field Model 870 in .308 caliber (This rifle is actually a Mossberg 800A, sold under license by Montgomery Ward as a "Western Field").
This rifle is topped off by a Bushnell "Scope Chief" 3X rifle scope.
2. Select an "Everyman Cast Bullet" for the test:
In this case I decided upon the Lee Precision C309-170-F Mold. This is a nominal 170 grain .309 mold. In my application with wheel weights it drops bullets at about 177 grains plus or minus depending on the batch of wheel weights.
Bullets for this test were derived from a casting session where about 250 bullets were cast. All were Water Quenched Wheel Weight Alloy.
3. Use an economical but accurate Scale:
I utilized a 1970's vintage RCBS 5-10 Balance Beam Scale. It has course measurements of 10 grains, with a fine adjustment threaded counter weight supporting measurement in 1/10th of a grain increments.
I have a small Frankford Arsenal digital scale; which I specifically decided Not To Use in this effort. It has a tendency to wander 3/10th to 5/10th a grain for up to 10 seconds when weighing bullets. Additionally, it has the same variation depending on where the bullet is placed o the scale. There is no apparent means of correcting the first variable condition; but I have drawn a set of "Cross Hairs" on the scale to identify the exact center to address the second condition. These variables were why I decided not to use a digital scale.
Bullets for the test were segregated into three groups. The first group was 177 grain (+) or (-) 0.2 grains. A second group of Heavy bullets were selected weighing about 178 grains (+) or (-) 0.3 grains. A third group of light bullets were selected weighing about 176 grains (+) or (-) 0.3 grains.
4. Use a common powder dispenser:
I utilized an RCBS Uniflow Powder Measure I purchased in the mid 1970s. The throw charge was adjusted to 13.7 grains of Unique powder as weighed by the RCBS 5-10 Balance scale. All loads were charged from the RCBS Powder dispenser. I made no further attempt to validate powder charges weights (e.g. I did NOT weigh each charge, but simply thre them through the Powder Dispenser).
5. Use a common set of Reloading Dies:
For this test I selected Lee's RGB (Really Great Buy) .308 dies.
6. Trim all Brass to same length:
For this test I used my Dillion RT1200 Trimmer. I would have preferred to keep with the "Everyman" theme by using my Lee .308 case trimmer, but my rechargeable drill died a few weeks ago and I have not replaced it. Years ago I would use the Lee Case Trimmer in a hand held mode for trimming; but due to hand fatigue and a touch of arthritis, I no longer do so.
7. Use a common Sizing/Lubrication method:
I utilized a Lyman 450 Lubrisizer with .311 sizing dies. For Lube, I selected Carnuba Red.