RDub
Member
Greetings
During the past several months I have been insatiably curious about the .38 Special 158gr Round Nose service load and duplicating that load. I have come across some inquires on forums as to what is an actual .38 Special factory duplication load for the 158gr RN service load that has been around forever but my curiosity wasn’t really satisfied.
I’ve undertaken a little research project in attempting to duplicate a .38 Special 158gr RN factory load, not only emphasizing velocity, but accuracy as well.
For decades now, I have always believed that 3.5 grs of Bullseye was the undisputed duplication load for 158gr lead bullets, so I wanted to determine if this is true also.
The only 158gr RN factory load I can find right now is the Rem-UMC load.
First thing I did was to get out my handy RCBS inertia bullet puller and examine three rounds and see what’s in there.
All three rounds had exactly 4.0 grains of a small flaked powder. I sprinkled some out on some paper and put some W231 along side for comparison.
So Rem is using a relatively fast powder here and small flakes for consistent metering.
Next I weighed the bullets and they were all 158.5 grains, and measured .358”.
Some might say that if we can’t use the exact components the factory is using then the whole exercise is ludicrous. Well, maybe true. But since the factory Round Nose bullets are not readily available at the retail level, we just have to use something close but different.
For this test I chose to use the old standby, the Lyman 358311 Round Nose cast bullet.
This batch is made from a 90/10% lead – tin mix and they weigh 159.something grains, and sized to .358”. They are lubed with Javalina bullet lube.
.
My initial test rounds were the following, just to give me a flavor of where I was with this bullet. These charges are just what my Little Dandy rotors threw out so I started there.
I guessed that I might get around 750 fps with the factory load so I loaded up some tester rounds using the SWAG method that I thought should get me about 750fps based on other work I have done.
I’m using a 4” S&W 686.
3.7 grs Bullseye
4.1 grs 700-X
4.8 grs UNIQUE
5.0 grs SR7625
5.1 grs Power Pistol
Federal cases and Remington primers.
Ok, so here is what happened at the range today.
25 yards
58°F
Oehler Mod 33 chronograph 10’ from muzzle
As you can see, the factory load (#6) was indeed right about there. Good extreme spread and accuracy not too bad.
3.7 grs of Bullseye (#9) was just about exact for duplicating this factory load. Accuracy is a little better than factory. If, I had loaded 3.5 grs it would have been shy of 760 fps.
4.1 grs of 700-X (#8) was a little much. I could drop down to 4.0grs or maybe 3.9grs. This powder also gave good accuracy, better than factory.
5.0 grs of SR7625 (11) was just about right on the money for what a 158gr +P load would give. I’ll try about 4.5 grs next time.
UNIQUE and Power Pistol (#10,12) was also past the mark a little bit.
The place I shot today needed a little brush clearing, which made my pulse not settle down the way I would've liked, so I think thats why the groups were a bit vertical.
So I’ll make some adjustments, shoot again and see what happens.
During the past several months I have been insatiably curious about the .38 Special 158gr Round Nose service load and duplicating that load. I have come across some inquires on forums as to what is an actual .38 Special factory duplication load for the 158gr RN service load that has been around forever but my curiosity wasn’t really satisfied.
I’ve undertaken a little research project in attempting to duplicate a .38 Special 158gr RN factory load, not only emphasizing velocity, but accuracy as well.
For decades now, I have always believed that 3.5 grs of Bullseye was the undisputed duplication load for 158gr lead bullets, so I wanted to determine if this is true also.
The only 158gr RN factory load I can find right now is the Rem-UMC load.
First thing I did was to get out my handy RCBS inertia bullet puller and examine three rounds and see what’s in there.
All three rounds had exactly 4.0 grains of a small flaked powder. I sprinkled some out on some paper and put some W231 along side for comparison.
So Rem is using a relatively fast powder here and small flakes for consistent metering.
Next I weighed the bullets and they were all 158.5 grains, and measured .358”.
Some might say that if we can’t use the exact components the factory is using then the whole exercise is ludicrous. Well, maybe true. But since the factory Round Nose bullets are not readily available at the retail level, we just have to use something close but different.
For this test I chose to use the old standby, the Lyman 358311 Round Nose cast bullet.
This batch is made from a 90/10% lead – tin mix and they weigh 159.something grains, and sized to .358”. They are lubed with Javalina bullet lube.
.
My initial test rounds were the following, just to give me a flavor of where I was with this bullet. These charges are just what my Little Dandy rotors threw out so I started there.
I guessed that I might get around 750 fps with the factory load so I loaded up some tester rounds using the SWAG method that I thought should get me about 750fps based on other work I have done.
I’m using a 4” S&W 686.
3.7 grs Bullseye
4.1 grs 700-X
4.8 grs UNIQUE
5.0 grs SR7625
5.1 grs Power Pistol
Federal cases and Remington primers.
Ok, so here is what happened at the range today.
25 yards
58°F
Oehler Mod 33 chronograph 10’ from muzzle
As you can see, the factory load (#6) was indeed right about there. Good extreme spread and accuracy not too bad.
3.7 grs of Bullseye (#9) was just about exact for duplicating this factory load. Accuracy is a little better than factory. If, I had loaded 3.5 grs it would have been shy of 760 fps.
4.1 grs of 700-X (#8) was a little much. I could drop down to 4.0grs or maybe 3.9grs. This powder also gave good accuracy, better than factory.
5.0 grs of SR7625 (11) was just about right on the money for what a 158gr +P load would give. I’ll try about 4.5 grs next time.
UNIQUE and Power Pistol (#10,12) was also past the mark a little bit.
The place I shot today needed a little brush clearing, which made my pulse not settle down the way I would've liked, so I think thats why the groups were a bit vertical.
So I’ll make some adjustments, shoot again and see what happens.
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