goodgrouper
tryingtobeabettergrouper
I have been doing some more testing of N133 in my 6ppc barrels over a chronograph and have found some interesting results. Some of you may remember my test I ran in the practice days leading up to the Cactus Classic involving several different lots of N133 in the barrel I used for the competition. Well, I'm on a new (well, newer anyway) barrel and just got a new lot of N133 so I thought it time to run another test.
All info comes from an Oehler 35 chrono on a 4' rod placed 10' from the muzzle and all aspects of the testing were kept as controlled as possible. The Harrells powder measure was in the shade during charging and the powder was kept in the shade for hours before and during testing. I did no sifting of powder or anything "extreme" like that. But I did make sure I used the same cases and made sure that all the powder had been tapped out of the case before throwing a new lot into it and I settled each lot of powder into the hopper before throwing any charges.
Temp was 63 degrees and it rained off and on most of the day. The Harrells setting for the whole experiment was 52.5 clicks. Fed 205 used throughout and 220 russian fireformed Lapua brass.
Anyhoo, the four lots tested were as follows:
14906 30-1-2007
14906 1-2-2007 (may be the same as the lot above but I thought I would test it anyway)
306/99 28-09-1999
and the newest lot of 28708 23-9-2008
So I will lay out the order of the information in the order of the list above.
First lot (14906 30-1-2007:
extreme spread 31 fps
average 3344 fps
standard deviation 15 fps
Weights of thrown powder measured on RCBS Chargemaster: 28.5, 28.5, 28.6,28.5 grains for average of 28.52 grains
Second lot:
extreme spread 28 fps
average 3307 fps
standard d. 14 fps
Weights: 28.6, 28.4, 28.6, 28.6 grains for average of 28.55 grains
Third lot:
extreme spread 27 fps
average 3311
standard d. 14
Weights: 28.6, 28.5, 28.4, 28.6 grains for average of 28.52 grains
Fourth lot (the new stuff)
extreme spread 17 fps
average 3233 fps
standard d. 8 f ps
Weights: 28.3, 28.2, 28.3, 28.2 grains for average of 28.25 grains
Then to check to see if this new lot was really that much different than the others, we fired this stuff in another gun which also was a 13.5" twist Krieger and it confirmed what my gun said. The new lot of 2008 N133 is definitely bulkier and won't throw to the same charge as the others. But not only that, but when the charge was increased to 53, it was slower still than it should have been in comparison only achieving 3313 fps from 3292 with 52.5 clicks in my friend's gun. The pressure curve that was seen in the other powders showed around a 35 to 40 fps increase with every half number on the Harrells and this new stuff was only going up 21 fps. But the good news: The new stuff still shoot darn good. It actually shot smaller groups than the 1999 lot did. But none of them were bad. All the lots of N133 shot in the ones. But the 2008 shot the tightest still. It's just slow. But who cares? It works anyway.
Conclusion:
3 out of the 4 lots of N133 were darn close to each other despite their 8 year difference. The last lot was a bit different but still shot fine.
On a side note, every powder threw a slightly lighter charge on the first throw if the powder was not settled into the hopper by lightly tapping the handle a few times. Just good to know. I always tap the powder but even then I still use the first charge or two as my foulers.
All info comes from an Oehler 35 chrono on a 4' rod placed 10' from the muzzle and all aspects of the testing were kept as controlled as possible. The Harrells powder measure was in the shade during charging and the powder was kept in the shade for hours before and during testing. I did no sifting of powder or anything "extreme" like that. But I did make sure I used the same cases and made sure that all the powder had been tapped out of the case before throwing a new lot into it and I settled each lot of powder into the hopper before throwing any charges.
Temp was 63 degrees and it rained off and on most of the day. The Harrells setting for the whole experiment was 52.5 clicks. Fed 205 used throughout and 220 russian fireformed Lapua brass.
Anyhoo, the four lots tested were as follows:
14906 30-1-2007
14906 1-2-2007 (may be the same as the lot above but I thought I would test it anyway)
306/99 28-09-1999
and the newest lot of 28708 23-9-2008
So I will lay out the order of the information in the order of the list above.
First lot (14906 30-1-2007:
extreme spread 31 fps
average 3344 fps
standard deviation 15 fps
Weights of thrown powder measured on RCBS Chargemaster: 28.5, 28.5, 28.6,28.5 grains for average of 28.52 grains
Second lot:
extreme spread 28 fps
average 3307 fps
standard d. 14 fps
Weights: 28.6, 28.4, 28.6, 28.6 grains for average of 28.55 grains
Third lot:
extreme spread 27 fps
average 3311
standard d. 14
Weights: 28.6, 28.5, 28.4, 28.6 grains for average of 28.52 grains
Fourth lot (the new stuff)
extreme spread 17 fps
average 3233 fps
standard d. 8 f ps
Weights: 28.3, 28.2, 28.3, 28.2 grains for average of 28.25 grains
Then to check to see if this new lot was really that much different than the others, we fired this stuff in another gun which also was a 13.5" twist Krieger and it confirmed what my gun said. The new lot of 2008 N133 is definitely bulkier and won't throw to the same charge as the others. But not only that, but when the charge was increased to 53, it was slower still than it should have been in comparison only achieving 3313 fps from 3292 with 52.5 clicks in my friend's gun. The pressure curve that was seen in the other powders showed around a 35 to 40 fps increase with every half number on the Harrells and this new stuff was only going up 21 fps. But the good news: The new stuff still shoot darn good. It actually shot smaller groups than the 1999 lot did. But none of them were bad. All the lots of N133 shot in the ones. But the 2008 shot the tightest still. It's just slow. But who cares? It works anyway.
Conclusion:
3 out of the 4 lots of N133 were darn close to each other despite their 8 year difference. The last lot was a bit different but still shot fine.
On a side note, every powder threw a slightly lighter charge on the first throw if the powder was not settled into the hopper by lightly tapping the handle a few times. Just good to know. I always tap the powder but even then I still use the first charge or two as my foulers.
