kawasakifreak77
09-12-2014, 02:38 AM
Dun dun dun!
Okay, seriously.
So it's relatively well known that the above ammunition (stuff in the white box) is not really subsonic, even in some gas guns which of course most blackout guys are running.
As some of you know, I'm a died in the wool blackout freak job & think this is the best daw gone thing since mini skirts & micro breweries...
In my rifle (AAC Micro 7, YHM Phanton always attached) they go supersonic, making an annoying crack like a high velocity .22
Hey if I bought subs, I want 'em to be sub!
So I started breaking down the rounds to make a truely subsonic load using whatever magical unicorn fart powder Remington puts in there.
I found several interesting things.
First off there appears to be two distinct loads I have. I thought they were all from the same run, as all boxes say 24122?
Regardless. The first few boxes I had bought have a slightly nicer looking bullet with a light crimp. The bullets in the boxes I had bought later on have odd looking teardrop shaped 'dents' near the tip & a HEAVY crimp.
Pulling them apart, the 'later' bullets are on average .050" longer than the 'early' bullets. 1.450" vs 1.500" respectively. Early bullets are cosmetically much nicer & later bullets have a 'waist' just below the cannalure averaging a whopping .295" from the crazy crimp job. I do really like the design of the bullet. It's a flatbase with a much longer ogive than the 220 SMK. Hopefully if this caliber keeps gaining steam like it has been, a bullet of similar construction will be released to the public for reloading.
Sorting the boxes, I have mostly early ones, so those went to the side & I'm burning up the late bullets first cause they're ugly.
Powder: it's a small grained stick powder. Charges are anywhere from 9.9 grains to 10.8 grains. Right about where I had guessed it would be. Seems pretty strange that the charge varies so much though. This is the first time I've tore down factory loads so maybe this is within spec? The early loads powder is ever so slighly glossier. I didn't notice it at first & I have very keen eyes.
Brass: relatively uniform. Shortest being 1.358" & longest being 1.364" so far. Most wind up between 1.359" & 1.362"
So I pull down a few boxes, load up my powder trickler & set up a ladder test at 9.0, 9.5 & 10.0 grains. OAL was set at 2.350" since I'm not restricted by magazine limitations as on ARs.
Temperature around 80° elevation 1550'
10.0 grains:
1112 fps
1136
1093
1112
1080
A bit too fast. Some just BARELY made a crack so I knew I was close. But in this warmer weather I know they'll crack come wintertime.
9.5 grains:
1058
1055
1021
1046
1038
Now we're making progress! 1043fps average with a 38fps ES. Not shabby I feel for a first go round. Reading articles by JD himself I noticed his
pattern of building sub loads to a 1040fps average, so that's what I've tailored my loads to. I figure he knows a lot more about this than I do!
I went ahead & fired off the last group since I didn't feel like pulling anymore ugly bullets.
9.0 grains:
987
949
979
940
938
I know some dudes say they like to go under 1000fps for maximum suppression. I honestly couldn't tell a difference. Both the 9.5 & 9.0 loads were air rifle quiet! Just what I want. :)
So I've pulled down a few more boxes of the later stuff & have loaded a full box at 9.5 grains for a more thorough test. Will chrony another 5 rounds then shoot for groups. If that all goes well wet telephone books will start getting punched next!
Will advise.
Okay, seriously.
So it's relatively well known that the above ammunition (stuff in the white box) is not really subsonic, even in some gas guns which of course most blackout guys are running.
As some of you know, I'm a died in the wool blackout freak job & think this is the best daw gone thing since mini skirts & micro breweries...
In my rifle (AAC Micro 7, YHM Phanton always attached) they go supersonic, making an annoying crack like a high velocity .22
Hey if I bought subs, I want 'em to be sub!
So I started breaking down the rounds to make a truely subsonic load using whatever magical unicorn fart powder Remington puts in there.
I found several interesting things.
First off there appears to be two distinct loads I have. I thought they were all from the same run, as all boxes say 24122?
Regardless. The first few boxes I had bought have a slightly nicer looking bullet with a light crimp. The bullets in the boxes I had bought later on have odd looking teardrop shaped 'dents' near the tip & a HEAVY crimp.
Pulling them apart, the 'later' bullets are on average .050" longer than the 'early' bullets. 1.450" vs 1.500" respectively. Early bullets are cosmetically much nicer & later bullets have a 'waist' just below the cannalure averaging a whopping .295" from the crazy crimp job. I do really like the design of the bullet. It's a flatbase with a much longer ogive than the 220 SMK. Hopefully if this caliber keeps gaining steam like it has been, a bullet of similar construction will be released to the public for reloading.
Sorting the boxes, I have mostly early ones, so those went to the side & I'm burning up the late bullets first cause they're ugly.
Powder: it's a small grained stick powder. Charges are anywhere from 9.9 grains to 10.8 grains. Right about where I had guessed it would be. Seems pretty strange that the charge varies so much though. This is the first time I've tore down factory loads so maybe this is within spec? The early loads powder is ever so slighly glossier. I didn't notice it at first & I have very keen eyes.
Brass: relatively uniform. Shortest being 1.358" & longest being 1.364" so far. Most wind up between 1.359" & 1.362"
So I pull down a few boxes, load up my powder trickler & set up a ladder test at 9.0, 9.5 & 10.0 grains. OAL was set at 2.350" since I'm not restricted by magazine limitations as on ARs.
Temperature around 80° elevation 1550'
10.0 grains:
1112 fps
1136
1093
1112
1080
A bit too fast. Some just BARELY made a crack so I knew I was close. But in this warmer weather I know they'll crack come wintertime.
9.5 grains:
1058
1055
1021
1046
1038
Now we're making progress! 1043fps average with a 38fps ES. Not shabby I feel for a first go round. Reading articles by JD himself I noticed his
pattern of building sub loads to a 1040fps average, so that's what I've tailored my loads to. I figure he knows a lot more about this than I do!
I went ahead & fired off the last group since I didn't feel like pulling anymore ugly bullets.
9.0 grains:
987
949
979
940
938
I know some dudes say they like to go under 1000fps for maximum suppression. I honestly couldn't tell a difference. Both the 9.5 & 9.0 loads were air rifle quiet! Just what I want. :)
So I've pulled down a few more boxes of the later stuff & have loaded a full box at 9.5 grains for a more thorough test. Will chrony another 5 rounds then shoot for groups. If that all goes well wet telephone books will start getting punched next!
Will advise.