OP
OP
Mr_Flintstone
Member
OK, here are the results. They should be fairly accurate (for my guns). The guns I used in testing were a service length 4” S&W Model 19 and a Henry Big Boy with a 20” octagonal barrel.
I took the highest +P load values from my various load manuals and online sources of data for the jacketed bullets to see how hard the loads could be pushed and still fall within SAAMI specs. For the cast loads I used loads that fell closest to the standard pressure value of 17,000 psi. I did this mainly to avoid the possibility of leading my barrels, and after testing, I didn’t notice any buildup of any kinds in either barrel. There was some carbon rings in the revolver cylinder, and I suspect also in the rifle. Each will receive a thorough cleaning afterwards.
The first thing I noticed was that the jacketed results and cast results were very different. Across the jacketed loads, the slower powders did much better the faster ones, but when using cast loads the percentage increase differences was much closer to one another.
I had expected IMR 4227 to do the best across the board before I began testing, but that wasn’t always the case. While it did, in many cases, have the highest overall velocity, it didn’t necessarily have the biggest increase in velocity. I suspect that’s because 4227 typically does much better at higher pressures with high load densities and with heavy bullets. This effect can partially be seen in the 158 gr jacketed results. The heavy bullets and high pressure produced a bigger increase in velocity than did the other powders. With the other bullets, the increase with 4227 was respectable, but less than the other powders.
Alliant 2400 seems to be the sweet spot for top end loads in 38 Special. It typically had the biggest increase in velocity, and in some cases had the highest overall velocity. The one instance where 2400 produced the lowest revolver velocity and second lowest rifle velocity was because load data for a different bullet was used because I couldn’t find exact data for the used bullet. I later found the correct data, but for testing the increase in velocity rather than highest overall velocity, the data worked fine so I didn’t redo the loads.
I was also rather impressed with AutoComp’s overall velocities and especially its increases in velocity. The only problem was that the only source for data is from Hodgdon, and it appears rather conservative. Nearly all of the loads were well below maximum pressure, more so it seems than many of Hodgdon’s other powders. I feel that this is an often overlooked, and undeservedly so, powder for 38 special. It produced high velocities at low pressure and big increases in velocity when switching from revolver to a rifle. I wish there was more load data from other sources, but it does quite well as it is.
I was a little let down with Unique’s performance overall. While it did produce good revolver length loads, I felt that given its reputation, it should have given bigger boosts in rifle loads. I guess that’s because it is faster than 4227, 2400, and AutoComp.
Titegroup, the fastest powder I tested, performed about how I expected. The fast powder combined with a small charge produced some respectable revolver velocities, but the rifle loads were more like shooting a .22 LR with the jacketed loads. It seemed to do much better with cast.
I realize that this is not an exhaustive test of powders, but it does range from fairly fast to slow powders. Much more testing than I can do with what I have on hand would give a much better overall picture. Nevertheless, I believe the data shows that slower powders do produce some velocities that punch above their weight class when fired from a rifle, especially with jacketed bullets. I believe that 4227 is probably too slow in many cases, but the large volumes of powder used in the loads produce low velocity spreads because a fraction of a grain difference has less of an effect than with the low charge fast powders like Titegroup. The same can be said of 2400, except that it is a touch faster than 4227. It does produce some phenomenal 38 special velocities from a rifle.
I wish I had some lubed cast bullets to try instead of coated bullets to see if the closeness of velocity increase was a result of the bullets being cast or because they were polymer/powder coated.
I took the highest +P load values from my various load manuals and online sources of data for the jacketed bullets to see how hard the loads could be pushed and still fall within SAAMI specs. For the cast loads I used loads that fell closest to the standard pressure value of 17,000 psi. I did this mainly to avoid the possibility of leading my barrels, and after testing, I didn’t notice any buildup of any kinds in either barrel. There was some carbon rings in the revolver cylinder, and I suspect also in the rifle. Each will receive a thorough cleaning afterwards.
The first thing I noticed was that the jacketed results and cast results were very different. Across the jacketed loads, the slower powders did much better the faster ones, but when using cast loads the percentage increase differences was much closer to one another.
I had expected IMR 4227 to do the best across the board before I began testing, but that wasn’t always the case. While it did, in many cases, have the highest overall velocity, it didn’t necessarily have the biggest increase in velocity. I suspect that’s because 4227 typically does much better at higher pressures with high load densities and with heavy bullets. This effect can partially be seen in the 158 gr jacketed results. The heavy bullets and high pressure produced a bigger increase in velocity than did the other powders. With the other bullets, the increase with 4227 was respectable, but less than the other powders.
Alliant 2400 seems to be the sweet spot for top end loads in 38 Special. It typically had the biggest increase in velocity, and in some cases had the highest overall velocity. The one instance where 2400 produced the lowest revolver velocity and second lowest rifle velocity was because load data for a different bullet was used because I couldn’t find exact data for the used bullet. I later found the correct data, but for testing the increase in velocity rather than highest overall velocity, the data worked fine so I didn’t redo the loads.
I was also rather impressed with AutoComp’s overall velocities and especially its increases in velocity. The only problem was that the only source for data is from Hodgdon, and it appears rather conservative. Nearly all of the loads were well below maximum pressure, more so it seems than many of Hodgdon’s other powders. I feel that this is an often overlooked, and undeservedly so, powder for 38 special. It produced high velocities at low pressure and big increases in velocity when switching from revolver to a rifle. I wish there was more load data from other sources, but it does quite well as it is.
I was a little let down with Unique’s performance overall. While it did produce good revolver length loads, I felt that given its reputation, it should have given bigger boosts in rifle loads. I guess that’s because it is faster than 4227, 2400, and AutoComp.
Titegroup, the fastest powder I tested, performed about how I expected. The fast powder combined with a small charge produced some respectable revolver velocities, but the rifle loads were more like shooting a .22 LR with the jacketed loads. It seemed to do much better with cast.
I realize that this is not an exhaustive test of powders, but it does range from fairly fast to slow powders. Much more testing than I can do with what I have on hand would give a much better overall picture. Nevertheless, I believe the data shows that slower powders do produce some velocities that punch above their weight class when fired from a rifle, especially with jacketed bullets. I believe that 4227 is probably too slow in many cases, but the large volumes of powder used in the loads produce low velocity spreads because a fraction of a grain difference has less of an effect than with the low charge fast powders like Titegroup. The same can be said of 2400, except that it is a touch faster than 4227. It does produce some phenomenal 38 special velocities from a rifle.
I wish I had some lubed cast bullets to try instead of coated bullets to see if the closeness of velocity increase was a result of the bullets being cast or because they were polymer/powder coated.
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