RDub
Member
Hello
This post is partly about IMR BLUE, but I also wanted to do update on an issue with a previous post regarding chronograph data.
http://smith-wessonforum.com/reloading/189366-357-mag-125gr-factory-duplication.html
I've been using the skyscreen II's with the Oehler 33 chronograph for years believing all was just fine. Recently it has come to my attention that maybe there is an issue with the II's. The Oehler folks have been most adamant about me to getting the skyscreen III's. The issue with the II's is apparently they are adversely susceptible to sonic blast. Not all ammunition is effected supposedly, just some of the high end decibel loads.
So I picked up a pair of the III's and took them out for a test run. Shot some /38's over both the II's and III's and the III's read a little faster, 10-20 fps. Hmm.
One of the things I wanted to shoot over the III's was a .357/125gr JHP/H-110 load out of a 4" barrel that I could not get the velocity I 'should' be getting. So while I was at it, testing three different primers might prove interesting.
So here is how that went..; Range 25 yards. Circles are 4".
Well looky here.. This is more like it.
Oehler tells me that the III's have much better shielding than the II's did. It is looking like this is true. Oehler fixed this issue long ago, but I didn't realize how significant this issue was.
So with this, I thought I should do a re-shoot with some other powders as well.
The Sierra bullets I shot last time are gone, but I have a bunch of these generic 125gr JHPs I got from NE Shooters Supply. They look much like the old Speer design but I can't be curtain. They should work just fine here. So five rounds were loaded up with H-110, 296, Blue Dot, AA #9, 2400, N110, Enforcer, 300-MP, and two loads of IMR BLUE.
Looking at this it's rather obvious that the Remington factory load can be duplicated and in fact safely exceeded with most of these powders. None of these loads produced any signs of excessive pressure. Cases fell out of the chambers. However, 14.0grs of IMR BLUE showed some primer flattening, not very much, just a little more than the rest.
14.0grs did shoot one the tightest groups and came in with the tightest standard deviation, but I wouldn't recommend going beyond 14.0grs.. No need to really, it tied with 22.0grs H-110 and that should be fast enough. When or if IMR BLUE is tested in the Lab with this application we'll know more about it. 13.6-7grs should duplicate the REM-UMC load. It is interesting that this 0.5gr. increment yielded almost 100 fps. IMR BLUE is showing some potential here.
As for the rest.. Well the skyscreen III's tell a much different story now.
Got a weird flyer with 2400, but that could have been me. 300-MR didn't like this bullet very much. AA#9 and 296 were nice solid loads with this bullet.
Overall the tightest group was the REM-UMC factory load. (6)
I believe this is more representative of the .357 Mag 125gr load out of a 4" barrel.
Here is a graph for today;
Hope this sheds some more light on IMR BLUE.
I apologize for any confusion or misleading.
This post is partly about IMR BLUE, but I also wanted to do update on an issue with a previous post regarding chronograph data.
http://smith-wessonforum.com/reloading/189366-357-mag-125gr-factory-duplication.html
I've been using the skyscreen II's with the Oehler 33 chronograph for years believing all was just fine. Recently it has come to my attention that maybe there is an issue with the II's. The Oehler folks have been most adamant about me to getting the skyscreen III's. The issue with the II's is apparently they are adversely susceptible to sonic blast. Not all ammunition is effected supposedly, just some of the high end decibel loads.
So I picked up a pair of the III's and took them out for a test run. Shot some /38's over both the II's and III's and the III's read a little faster, 10-20 fps. Hmm.
One of the things I wanted to shoot over the III's was a .357/125gr JHP/H-110 load out of a 4" barrel that I could not get the velocity I 'should' be getting. So while I was at it, testing three different primers might prove interesting.
So here is how that went..; Range 25 yards. Circles are 4".
Well looky here.. This is more like it.
Oehler tells me that the III's have much better shielding than the II's did. It is looking like this is true. Oehler fixed this issue long ago, but I didn't realize how significant this issue was.
So with this, I thought I should do a re-shoot with some other powders as well.
The Sierra bullets I shot last time are gone, but I have a bunch of these generic 125gr JHPs I got from NE Shooters Supply. They look much like the old Speer design but I can't be curtain. They should work just fine here. So five rounds were loaded up with H-110, 296, Blue Dot, AA #9, 2400, N110, Enforcer, 300-MP, and two loads of IMR BLUE.
Looking at this it's rather obvious that the Remington factory load can be duplicated and in fact safely exceeded with most of these powders. None of these loads produced any signs of excessive pressure. Cases fell out of the chambers. However, 14.0grs of IMR BLUE showed some primer flattening, not very much, just a little more than the rest.
14.0grs did shoot one the tightest groups and came in with the tightest standard deviation, but I wouldn't recommend going beyond 14.0grs.. No need to really, it tied with 22.0grs H-110 and that should be fast enough. When or if IMR BLUE is tested in the Lab with this application we'll know more about it. 13.6-7grs should duplicate the REM-UMC load. It is interesting that this 0.5gr. increment yielded almost 100 fps. IMR BLUE is showing some potential here.
As for the rest.. Well the skyscreen III's tell a much different story now.
Got a weird flyer with 2400, but that could have been me. 300-MR didn't like this bullet very much. AA#9 and 296 were nice solid loads with this bullet.
Overall the tightest group was the REM-UMC factory load. (6)
I believe this is more representative of the .357 Mag 125gr load out of a 4" barrel.
Here is a graph for today;
Hope this sheds some more light on IMR BLUE.
I apologize for any confusion or misleading.
