Pilgrim
06-02-2006, 01:05 PM
I've been trying to get a load worked up for the double rifle lately. Trust me, they can be frustrating.
The first problem I'm dealing with is holding the rifle consistently. With my hard kickers, I've learned to hold them firmly to reduce felt recoil. With my double rifle, that technique causes the bullets to cross at 100 yds. Just by altering the hold, I can cause the bullet impact to shift by as much as 8" @ 100 yds. Nuts...lots to learn/relearn with this rifle, including how to hold this rifle consistently. When I do my part, it's a real shooter, last time out shooting factory ammo, it consistently grouped both barrels into an inch or less (same group for both barrels) at 100 yds. That is unusual to say the least for a double rifle. Anyway...I've almost got my loads worked out and yesterday head on out to the range to verify they group one last time before I load up a bunch of 'em. Here is where things went weird on me. The last time out to the range, same components, etc., the weather was in the low 70's. Velocities with the H4831SC and the Nosler 286 gr were about 2230 fps using a CCI 200 to light it off. Since the case is a real long one (imagine a stretched 30-40, necked up to 35+) I thought a magnum primer might help load consistency, so I loaded up a few with CCI 250's and yesterday headed off to the "proving grounds". Temp yesterday was in the mid-80's. Everybody KNOWS that higher temperatures will result in higher pressures and higher velocities. Right???? Nope. The same loads with the CCI 200 that chronographed 2230 last week chronographed 2130 to 2150 this week. The loads over the CCI 250 all chronographed at 2260 or so. Go figure. I'm going to try a heavier crimp and magnum primers for the next go around. The velocities have to be about 2230 for the barrels to regulate, so...back to the loading room.
The next thing that I thought might be of interest involved my 1886 Extra Light (.45-70). I've been (slowly) working up loads for this rifle using the RCBS 45-405 and 45-325. The 45 - 405 casts right at 425 gr ready to load, while the 45 - 325 casts at about 340 ready to load (WW + 2%). The 45 - 405 2ill be my serious work load and reaching 1900 to 2000 fps is no problem with 4895 or 2015 powders. Recoil of those loads in a 7 # rifle is pretty fierce, so depending on how tired I am and how late in the shooting session it is, groups suffer consideable. I've gotten groups around 1.5" to as much as 3" with the same loads at 50 yards. More work to do with the heavy load for sure. The light load uses the 45 - 325. I've been experimenting with both surplus 4759 and XMP 5744 powders under this bullet. I've noticed that the bullet (ACWW + 2%) lubed with LBT blue is giving me light leading wash at the muzzle when velocities exceed around 1500 fps. Since I've shot the heavy test loads after this, perhaps that also is impacting group size with those. Anyway, back to my story...With 25 gr. of 4759, the case looked very empty, so I decided to try the same load with no filler, kapok (1.1 gr.) and dacron (0.9 gr.) to see what difference there might be in velocity and accuracy. Here is what I found (5 shot groups @ 50 yds)...
No filler; V = 1448 fps, Sd = 23 // 4 in ~ 1" with one flyer out about 2"
Kapok ; V = 1517 fps, Sd = 12 // 4 in ~ 1.5" with one flyer out ~ 3", the group was "vertical" so I suspect it was me since the velocities were so consistent. I'm going to retest this one, but with 23 and 24 gr 4759 to lower the velocity into the 1400's.
Dacron ; V = 1502 fps, Sd = 6 // 4 in ~ 1/2" with one flyer out about 1.5" or so. This load will also be retested with 23, 24, and 25 gr 4759.
Why the fliers? I dunno, all of the shots felt about the same with the sight picture about the same. Perhaps I was getting tired as this testing was after the double rifle testing. FWIW...Pilgrim
The first problem I'm dealing with is holding the rifle consistently. With my hard kickers, I've learned to hold them firmly to reduce felt recoil. With my double rifle, that technique causes the bullets to cross at 100 yds. Just by altering the hold, I can cause the bullet impact to shift by as much as 8" @ 100 yds. Nuts...lots to learn/relearn with this rifle, including how to hold this rifle consistently. When I do my part, it's a real shooter, last time out shooting factory ammo, it consistently grouped both barrels into an inch or less (same group for both barrels) at 100 yds. That is unusual to say the least for a double rifle. Anyway...I've almost got my loads worked out and yesterday head on out to the range to verify they group one last time before I load up a bunch of 'em. Here is where things went weird on me. The last time out to the range, same components, etc., the weather was in the low 70's. Velocities with the H4831SC and the Nosler 286 gr were about 2230 fps using a CCI 200 to light it off. Since the case is a real long one (imagine a stretched 30-40, necked up to 35+) I thought a magnum primer might help load consistency, so I loaded up a few with CCI 250's and yesterday headed off to the "proving grounds". Temp yesterday was in the mid-80's. Everybody KNOWS that higher temperatures will result in higher pressures and higher velocities. Right???? Nope. The same loads with the CCI 200 that chronographed 2230 last week chronographed 2130 to 2150 this week. The loads over the CCI 250 all chronographed at 2260 or so. Go figure. I'm going to try a heavier crimp and magnum primers for the next go around. The velocities have to be about 2230 for the barrels to regulate, so...back to the loading room.
The next thing that I thought might be of interest involved my 1886 Extra Light (.45-70). I've been (slowly) working up loads for this rifle using the RCBS 45-405 and 45-325. The 45 - 405 casts right at 425 gr ready to load, while the 45 - 325 casts at about 340 ready to load (WW + 2%). The 45 - 405 2ill be my serious work load and reaching 1900 to 2000 fps is no problem with 4895 or 2015 powders. Recoil of those loads in a 7 # rifle is pretty fierce, so depending on how tired I am and how late in the shooting session it is, groups suffer consideable. I've gotten groups around 1.5" to as much as 3" with the same loads at 50 yards. More work to do with the heavy load for sure. The light load uses the 45 - 325. I've been experimenting with both surplus 4759 and XMP 5744 powders under this bullet. I've noticed that the bullet (ACWW + 2%) lubed with LBT blue is giving me light leading wash at the muzzle when velocities exceed around 1500 fps. Since I've shot the heavy test loads after this, perhaps that also is impacting group size with those. Anyway, back to my story...With 25 gr. of 4759, the case looked very empty, so I decided to try the same load with no filler, kapok (1.1 gr.) and dacron (0.9 gr.) to see what difference there might be in velocity and accuracy. Here is what I found (5 shot groups @ 50 yds)...
No filler; V = 1448 fps, Sd = 23 // 4 in ~ 1" with one flyer out about 2"
Kapok ; V = 1517 fps, Sd = 12 // 4 in ~ 1.5" with one flyer out ~ 3", the group was "vertical" so I suspect it was me since the velocities were so consistent. I'm going to retest this one, but with 23 and 24 gr 4759 to lower the velocity into the 1400's.
Dacron ; V = 1502 fps, Sd = 6 // 4 in ~ 1/2" with one flyer out about 1.5" or so. This load will also be retested with 23, 24, and 25 gr 4759.
Why the fliers? I dunno, all of the shots felt about the same with the sight picture about the same. Perhaps I was getting tired as this testing was after the double rifle testing. FWIW...Pilgrim