Mr_Flintstone
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I was discussing this on another forum, and I'd like input from some of you guys; since a lot of you deal with loading .38 caliber rounds.
When I have a .38 Special case that has been trimmed too much or has a slightly damaged case mouth, but is otherwise good shape, I trim it down to .38 Long Colt length and use it for a plinking round out of my Model 19 or Taurus Model 85.
Since most data for the .38 LC are rather anemic, and completely omits the pressures produced, while the max pressure of the .38 LC is approx 12,000 CUP, I was wondering whether I could use .38 Special 148 gr wadcutter data for the .38 LC. They have similar available case size, and since I'd be shooting them out of a +P rated .38 Special or a .357 Magnum it seems possible. Here's the part I'd like some input on.
I measured the cases of some factory once-fired .38 special, and my trimmed .38 LC and got the following:
.38 Special Case Length 1.145" and Inside Depth 0.98"
.38 Long Colt Case Length 1.015" and Inside Depth 0.85"
From what I found on the Internet (I don't have any on hand), a 148 gr DEWC has a length of 0.575" and a crimp groove at 0.475" to 0.483" depending on brand. I also measured the seating depth of a 125 gr lead TC bullet and a 140 gr TC bullet and got seating depths of 0.265" and 0.300" respectively.
Using the crimp groove of the wadcutter, I get a remaining case depth of 0.505" in the .38 Special. Using the 125 gr and 140 gr TC bullets in the Long Colt case, I get 0.585" and 0.550" respectively; which means that there is more available case volume in the Long Colt loads than the .38 Special wadcutter load. Even more so if the wadcutter is seated all the way flush.
Since there is equal or more case volume in the LC load, and a lighter bullet, shouldn't I get slightly less case pressure from loading a 125 or 140 gr lead bullet in a LC case than from a 148 gr wadcutter in a .38 special case using the same load data? If so, I could use a full wadcutter load in a .38 LC case with a 125 gr lead bullet and get close to 900 fps out of a 4" barrel and close to 850 fps with a 140 gr bullet with less than 12000 CUP pressure.
When I have a .38 Special case that has been trimmed too much or has a slightly damaged case mouth, but is otherwise good shape, I trim it down to .38 Long Colt length and use it for a plinking round out of my Model 19 or Taurus Model 85.
Since most data for the .38 LC are rather anemic, and completely omits the pressures produced, while the max pressure of the .38 LC is approx 12,000 CUP, I was wondering whether I could use .38 Special 148 gr wadcutter data for the .38 LC. They have similar available case size, and since I'd be shooting them out of a +P rated .38 Special or a .357 Magnum it seems possible. Here's the part I'd like some input on.
I measured the cases of some factory once-fired .38 special, and my trimmed .38 LC and got the following:
.38 Special Case Length 1.145" and Inside Depth 0.98"
.38 Long Colt Case Length 1.015" and Inside Depth 0.85"
From what I found on the Internet (I don't have any on hand), a 148 gr DEWC has a length of 0.575" and a crimp groove at 0.475" to 0.483" depending on brand. I also measured the seating depth of a 125 gr lead TC bullet and a 140 gr TC bullet and got seating depths of 0.265" and 0.300" respectively.
Using the crimp groove of the wadcutter, I get a remaining case depth of 0.505" in the .38 Special. Using the 125 gr and 140 gr TC bullets in the Long Colt case, I get 0.585" and 0.550" respectively; which means that there is more available case volume in the Long Colt loads than the .38 Special wadcutter load. Even more so if the wadcutter is seated all the way flush.
Since there is equal or more case volume in the LC load, and a lighter bullet, shouldn't I get slightly less case pressure from loading a 125 or 140 gr lead bullet in a LC case than from a 148 gr wadcutter in a .38 special case using the same load data? If so, I could use a full wadcutter load in a .38 LC case with a 125 gr lead bullet and get close to 900 fps out of a 4" barrel and close to 850 fps with a 140 gr bullet with less than 12000 CUP pressure.