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Powder for 280 AI with Swift Scirocco
- Thread starter Nimrod84
- Start date
- Thread starter
- #22
Dwh7271,
I'll let you know on the IMR 4955 with the Sciroccos; I probably won't be able to test it out this weekend... It worked very well with 175 grain Nosler Partitions out of one my 280 Rem. I did ask for a sanity check on a 52.8 grain load of 4955 at: viewtopic.php?f=4&t=35553.
Accuracy and ES was "acceptable" but not outstanding - normally around 1.25-1.5" for 5 shots at 100 yards and about 2.5" groups at 175 yards with 5 shots and a 2.5-8 scope. 52.8 grains of 4955 was providing about 2650 fps. I don't have my record book available to recount the ES but (I think and I want to stress "think") it was around 50 fps (old Shooting Chrony) and I think 53.3 grains was pushing the 175's into the low 2700s fps and I was not getting any pressure signs. Playing with the COAL would have probably tightened up the groups in the 2600-2700 fps range, but powder & bullets were running low and I didn't want to purchase more on the hope of getting it settled. Barrel was a 1 in 10 twist, so I opted to switch to RL-22 and 160 grain Accubonds that were waiting in the wings.
Temp stability seemed fine as far as I tested, original testing in the 30-40 F range and later test into the 80's. Again, I can't provide any numbers at the moment. The promised copper fouling reduction didn't seem to occur for me with the 175 grain Partitions. IMR 4451 does seem to significantly cut copper fouling in two 30-06's that use it with 165 grain Core-Lokts at moderate pressure / velocity (54.2-54.3 grains of 4551). So I think the Enduron's copper fighting ability varies on pressure and jacket type.
I'll let you know on the IMR 4955 with the Sciroccos; I probably won't be able to test it out this weekend... It worked very well with 175 grain Nosler Partitions out of one my 280 Rem. I did ask for a sanity check on a 52.8 grain load of 4955 at: viewtopic.php?f=4&t=35553.
Accuracy and ES was "acceptable" but not outstanding - normally around 1.25-1.5" for 5 shots at 100 yards and about 2.5" groups at 175 yards with 5 shots and a 2.5-8 scope. 52.8 grains of 4955 was providing about 2650 fps. I don't have my record book available to recount the ES but (I think and I want to stress "think") it was around 50 fps (old Shooting Chrony) and I think 53.3 grains was pushing the 175's into the low 2700s fps and I was not getting any pressure signs. Playing with the COAL would have probably tightened up the groups in the 2600-2700 fps range, but powder & bullets were running low and I didn't want to purchase more on the hope of getting it settled. Barrel was a 1 in 10 twist, so I opted to switch to RL-22 and 160 grain Accubonds that were waiting in the wings.
Temp stability seemed fine as far as I tested, original testing in the 30-40 F range and later test into the 80's. Again, I can't provide any numbers at the moment. The promised copper fouling reduction didn't seem to occur for me with the 175 grain Partitions. IMR 4451 does seem to significantly cut copper fouling in two 30-06's that use it with 165 grain Core-Lokts at moderate pressure / velocity (54.2-54.3 grains of 4551). So I think the Enduron's copper fighting ability varies on pressure and jacket type.
- Thread starter
- #24
Dwh7271,
I got out last Saturday with the IMR 4955 and Swift Sciroccos. I don't have a lot of things I can confidently report as the weather was pretty horrendous. My Oehler 35p wasn't giving me a proof reading; I think the moisture or static from the storms was shorting out one of the sensors. So I am a bit suspect as to the accuracy of my velocity readings.
Additionally, my velocity was significantly higher than what Hodgdon indicates with the Scirocco and I had a flattened primer at 59 grains. Hodgdon indicates 60.3 grains of IMR 4955 as max at 2859 fps; I thought Hodgdon's max velocity was around 2950 fps otherwise I would have stopped at 58.5 grains. I was going from memory rather than going to the vehicle to retrieve my notes.
I took 4 shots and accuracy looks very promising with the first and forth shot touching and the third shot about a quarter inch away. The second shot I pulled.
Fire formed 280 Hornady brass - with roughly 74 grains of H20 capacity.
IMR 4955 powder
CCI 200 primer
150 grain Swift Scirocco at 3.27-3.273" COAL
Charge weight - Velocity
57.1 - 2862
58 - 2886
58.5 compressed - 2932
59 compressed - 2962 - flattened primer
My current plan, unless some-one talks me out of it, is to shoot some groups at 56, 56.5 and 57 grains and see if any of those group and see what velocity I get on a good day. One thing that indicates that these velocities are valid is that I had a work-up for 154 gr SST's with IMR 4831 and they were running about 175-200 fps slower than book (mid 2700 fps and book called for 2900 fps), and that matches up with my 160 gr AccuBond running slow at 2700 fps with 58.6 grains of H4831SC.
I got out last Saturday with the IMR 4955 and Swift Sciroccos. I don't have a lot of things I can confidently report as the weather was pretty horrendous. My Oehler 35p wasn't giving me a proof reading; I think the moisture or static from the storms was shorting out one of the sensors. So I am a bit suspect as to the accuracy of my velocity readings.
Additionally, my velocity was significantly higher than what Hodgdon indicates with the Scirocco and I had a flattened primer at 59 grains. Hodgdon indicates 60.3 grains of IMR 4955 as max at 2859 fps; I thought Hodgdon's max velocity was around 2950 fps otherwise I would have stopped at 58.5 grains. I was going from memory rather than going to the vehicle to retrieve my notes.
I took 4 shots and accuracy looks very promising with the first and forth shot touching and the third shot about a quarter inch away. The second shot I pulled.
Fire formed 280 Hornady brass - with roughly 74 grains of H20 capacity.
IMR 4955 powder
CCI 200 primer
150 grain Swift Scirocco at 3.27-3.273" COAL
Charge weight - Velocity
57.1 - 2862
58 - 2886
58.5 compressed - 2932
59 compressed - 2962 - flattened primer
My current plan, unless some-one talks me out of it, is to shoot some groups at 56, 56.5 and 57 grains and see if any of those group and see what velocity I get on a good day. One thing that indicates that these velocities are valid is that I had a work-up for 154 gr SST's with IMR 4831 and they were running about 175-200 fps slower than book (mid 2700 fps and book called for 2900 fps), and that matches up with my 160 gr AccuBond running slow at 2700 fps with 58.6 grains of H4831SC.
I'll second Dwh7271, except I am running 59.5 gr of RL 26 with 160 AccuBond. Cci br2. Norma fire formed brass. 0.01 off the lands. 2920 fps in a 24" barrel. Group was 0.4".
that said I tested about 50 rounds loaded with varying charges of RL 23. Best group was 1.0" at 2960 fps with 59.0 gr of RL 23. started getting light extractor swipes at 59.3 gr and 3015 fps. Sticky bolt lift at 59.6 gr and 3025 fps. Avg temperature was 87. Use at your own risk
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that said I tested about 50 rounds loaded with varying charges of RL 23. Best group was 1.0" at 2960 fps with 59.0 gr of RL 23. started getting light extractor swipes at 59.3 gr and 3015 fps. Sticky bolt lift at 59.6 gr and 3025 fps. Avg temperature was 87. Use at your own risk
Dwh7271":30qmql4g said:Nimrod;
I'll be interested to see how the 4955 works.
My 160 AB load was 60 gr of RL26 for what it's worth.
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- Thread starter
- #26
You bet. COAL = 3.512"
my CBTO = 2.952" which is what I use
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my CBTO = 2.952" which is what I use
Nimrod84":2u7l5ect said:jspickar,
Thank you for the feedback, a pound of RL-26 is on my list to acquire.
Do you mind supplying the COAL of your load?
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- Thread starter
- #28
- Thread starter
- #30
Dwh7271,
I have a quick update; fired off the 56, 56.5 and 57 grain workups using IMR 4955 (3 rounds at 56-56.5 and 4 rounds at 57 grains) and 150 grain Sciroccos. Nothing grouped well (3-6 inches) and the ES was pretty high. I had some shade move in on the chronograph which might have played with the numbers and I was shooting at 175 yds without good support and significant mirage so some of the inaccuracy is likely from me. My 160 grain AccuBond over H4831sc gave consistent velocity early in the day, but I was getting some fliers (2 touching with the 3rd about 1.25" away) - indicating that I wasn't on top of my game... Having wrote that, the combination of high ES and poor accuracy tells me that this isn't looking like a peanut butter and jelly combo and that it will / would take a significant amount of time and resources to play with the seating depth.
57 grains of IMR 4955 had them going about 2840 fps with a seating depth of 3.27"ish, 56 grains with the Scirocco seated at just under 3.32" were running about the same velocity. The 56.5 grain loads were a little slower, around 2790ish, but again the high ES makes it tough to really say. I fired these off at the end of range session consisting of four 154 grain SST's and seven 160 grain Accubonds and there does not look to be much copper in the barrel. I haven't run solvent / patches through to get an actual read. I had run patch-out through the bore prior to shooting, so the barrel was pretty de-coppered prior to shooting.
I have a quick update; fired off the 56, 56.5 and 57 grain workups using IMR 4955 (3 rounds at 56-56.5 and 4 rounds at 57 grains) and 150 grain Sciroccos. Nothing grouped well (3-6 inches) and the ES was pretty high. I had some shade move in on the chronograph which might have played with the numbers and I was shooting at 175 yds without good support and significant mirage so some of the inaccuracy is likely from me. My 160 grain AccuBond over H4831sc gave consistent velocity early in the day, but I was getting some fliers (2 touching with the 3rd about 1.25" away) - indicating that I wasn't on top of my game... Having wrote that, the combination of high ES and poor accuracy tells me that this isn't looking like a peanut butter and jelly combo and that it will / would take a significant amount of time and resources to play with the seating depth.
57 grains of IMR 4955 had them going about 2840 fps with a seating depth of 3.27"ish, 56 grains with the Scirocco seated at just under 3.32" were running about the same velocity. The 56.5 grain loads were a little slower, around 2790ish, but again the high ES makes it tough to really say. I fired these off at the end of range session consisting of four 154 grain SST's and seven 160 grain Accubonds and there does not look to be much copper in the barrel. I haven't run solvent / patches through to get an actual read. I had run patch-out through the bore prior to shooting, so the barrel was pretty de-coppered prior to shooting.
- Thread starter
- #32
Dwh7271,
I'll let you know if I do anymore testing with IMR 4955 this year; I have enough powder for about 10 more rounds. Bow season starts Oct. 1st so I'm probably going to be in the woods rather than at the range.
I suspect that I could get the Scirocco's to work IMR 4955, given my first impression... However, I don't have enough powder left to really make it worth my while before hunting season; as I would need to redo load development with a new can.
FYI - 30-06 using 58 grains of IMR 4955 with 180 grain NP was giving between 2750-2800 fps in 40s-50s degree weather. CCI 200 primer and I believe Norma cases. Accuracy was good enough out to 175 yards and I could and should have tweaked COAL as the primary rifle I was testing consistently had two touching and one out. I was trying to get a load that would work in two 30-06s and I was seating somewhat deep for the primary rifle that I was testing. The 50 fps ES range is due to my older shooting crony which would normally vary that much depending on ambient light (clouds and sun angle); so I can't say if the rounds were closer to 2750 or 2800 fps. 58.5 grains was pretty close to max in the rifle. No pressure signs, but velocity did not increase and their was some compression on the powder; I figured 58 grains was a good enough place to be. H4831SC needed about 60 grains to hit 2700-2750 fps, so IMR 4955 was slightly more efficient however I did not see much improvement in copper fouling...
And that is all my experiences with IMR 4955.
I think IMR 4955 is designed for high pressure (above 60K psi) rounds; and lower pressures won't atomize the tin / bismuth or what ever they are using to minimize copper fouling. So 4955 in a 270 WIN with 140-150 grainers might be a real good combo, and I suspect it should shine in the 280 AI as well.
I'll let you know if I do anymore testing with IMR 4955 this year; I have enough powder for about 10 more rounds. Bow season starts Oct. 1st so I'm probably going to be in the woods rather than at the range.
I suspect that I could get the Scirocco's to work IMR 4955, given my first impression... However, I don't have enough powder left to really make it worth my while before hunting season; as I would need to redo load development with a new can.
FYI - 30-06 using 58 grains of IMR 4955 with 180 grain NP was giving between 2750-2800 fps in 40s-50s degree weather. CCI 200 primer and I believe Norma cases. Accuracy was good enough out to 175 yards and I could and should have tweaked COAL as the primary rifle I was testing consistently had two touching and one out. I was trying to get a load that would work in two 30-06s and I was seating somewhat deep for the primary rifle that I was testing. The 50 fps ES range is due to my older shooting crony which would normally vary that much depending on ambient light (clouds and sun angle); so I can't say if the rounds were closer to 2750 or 2800 fps. 58.5 grains was pretty close to max in the rifle. No pressure signs, but velocity did not increase and their was some compression on the powder; I figured 58 grains was a good enough place to be. H4831SC needed about 60 grains to hit 2700-2750 fps, so IMR 4955 was slightly more efficient however I did not see much improvement in copper fouling...
And that is all my experiences with IMR 4955.
I think IMR 4955 is designed for high pressure (above 60K psi) rounds; and lower pressures won't atomize the tin / bismuth or what ever they are using to minimize copper fouling. So 4955 in a 270 WIN with 140-150 grainers might be a real good combo, and I suspect it should shine in the 280 AI as well.
