N133

M

mturner

Member
I just purchased lot #140077 N133, packing date of 6-23-14. I have been shooting lot # 26608 N133, packing date of 5-7-2008. I was wondering if anyone knows how the later lots compare on burn rate. I haven't had a chance to chronograph the new lot yet. I did compare the density of the two lots, and came up with these numbers for 20 charges of each averaged. The measure setting was not changed.

Old lot averaged 39.55gr.
New lot averaged 39.1gr.

I hope the newer lot is faster burning since I lost almost .5 gr. in weight. The load of around 39.5gr was what I was using behind a 118gr bullet for a velocity of 3060 fps, and it shoots well. There just isn't much room left in the case for more powder if the newer lot doesn't make the velocity. I do have other powders like H322, H4198, and 2015 that will make a lot more velocity, but the N133 seems to be one of the better powders for small aggs.

Michael
 
I have heard that lots are close by weight, not density, so you might start by determining the measure setting that throws the same charge weight as you were using before. Let us know how it goes.
 
It is very close

Boyd Allen said:
I have heard that lots are close by weight, not density, so you might start by determining the measure setting that throws the same charge weight as you were using before. Let us know how it goes.
Click to expand...

Boyd,
I tired what you said. Normally I would start lower with an unknown powder, but N133 is a tad on the slow side for the 118gr bullet, so I just went for it. I used 39.5 gr of each lot. All powder charges were weighed. The newer lot proves to be a little slower by volume, but slightly faster by weight. Temperature was 58 degrees, and it is overcast and rainy. Barrel length is 24". Bullet is a 118gr on a .925" jacket with a 9 ogive. I alternated between both powders with each shot. I did not want to shoot all of the first powder, and then the second powder with a more fouled barrel.

lot # 26608 N133 at 39.5gr
3034
3042
3046
3049

Average = 3043 fps

lot #140077 N133 at 39.5gr
3052
3056
3059
3065

Average = 3058 fps

Michael
 
There was an article a while back in Precision Shooting that dealt with moisture content, and its effect on weight of 133. From the most saturated to artificially bone dry, the difference in weight for the same powder was about 2% and the swing in velocities was remarkable at the extremes. My guess is that with chronograph readings that close, the difference could be in "conditioning". I scanned the article. PM me if you are interested.
 
Keep in mind

The velocity increase was 15 fps over the older lot of powder. That would probably be closer to 30 fps in a 6PPC, because the more the case is necked down, the more the increase would be exaggerated. Also remember that I had to increase the measure setting by over 1% to achieve the same charge weight, so if you are simply going by volume alone, the newer lot is actually slower. Also the 6PPC would have a quicker pressure peak, which can have a very large effect on burn rate. In the 30-30, I find it very easy to make much more velocity with Benchmark, because I can get 42.5 gr in the case for a velocity of 3170 fps. In the 6PPC, some might say that N133 is easier to make velocity than Benchmark. My point is this. My testing might give shooters with hunter class cases a better idea of actual burn rates than 6PPC shooters. My advice for the 6PPC would be to start around 28.5gr with the new lot of N133, and go up or down to find a tune.

Michael
 
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