Has anyone here done tests of one lot of a given powder against another lot -- say two different lots of IMR4350 -- to see how consistent the results are, lot to lot?

Also, do some powder manufacturers do better, lot to lot, than others. By that I mean are the lot to lot variations of some powder manufacturers smaller than those of others? Has anyone here done tests that could answer these questions?

Lloyd,

I was on another list discussing H110 and W296. These are now the same powder packaged differently. In any case, the question was why there appeared to be a difference in the performance of the powder in the manuals of different bullet makers. Supposedly, they are using the same bullets, loaded to the same COL, with the same primers, in the same barrels and with the same pressure sensing measures, etc. So... in frustration I finally sat down with all my manuals and recorded those instances where BOTH H110 and W296 were tested by the manual.

You can see the resulting spreadsheet (which could be modified and improved, no doubt) at http://www.cfw.com/~parslowb/H110W296Comparison.xls (you may have to cut and paste the address to your browser). To sum up for those without Excel, the average difference in charge weights AND performance in fps between the "2" powders was 2% or less.

It is my contention that if there is this much difference lot to lot (and you know that they probably don't split lots between the 2 companies) then it is imperative that you work up loads every time you buy into a new lot. I've NOT been doing that, but I will be.

Also, there some anamolous differences in which the max charges for the 2 powders differed by as much as 32% with a 14% difference in performance as measure by fps with that particular bullet.

With the given information you could do some more figuring. Feel free to use the spreadsheet. I'd like to see what you come up with.

My experience with IMR (formerly DuPont) 4198, 3031, 4895, 4064, 4320, and 4350 powders for the past 50 years has shown them to be EXTREMELY CONSISTENT!! I have experienced quite a lot of variation in the performance of Norma powders in the 1970.s, particularly in N205, which has been replaced by MRP. MRP appears more consistent than N205. Hodgdon H322, H335, and H380 have also been rather consistent for me.

I've had good luck with IMR powders, as well as Hodgdon powders. I haven't tried many Alliant powders, but I've heard several folks lament huge lot to differences in RL22, for what that's worth.

My load development method allows for the development of a load that is largely immune to minor differences in powder lots. My post in this thread gives a basic overview of the method:

http://www.serveroptions.com/ubb/ultimatebb.php?ubb=get_topic;f=6;t=005860

Suffice it to say that a properly developed load can tolerate some variation in powder lots without altering its performance beyond MOA.

Dan Newberry
green 788

LE270,
I ran a series of test over a two and a half year period With Hodgdon Varget in my daughters 7mm-08. I wanted too see for myself if it was as consistent as they claimed as well as it's lack of sensitivity to temperature changes. During this test I used three different lots of powder. I fired test groups on the hottest as well as the coldest days we had. Hodgdon claims an extreme velocity spread of 8fps in test fired at zero, seventy and 125 degrees. The temperatures I fired at were between teens and about 104 degrees. The extreme velocity spread I averaged was 19 fps. I've seen spreads of 150 fps in IMR powders. As a result of this test I now load only Hodgdon extruded powders. While I haven't conducted the same test on other Hodgdon powders, they seem to perform with the same consistency. I have used Benchmark,4895,4350, 4831SC and H-1000 powders besides Varget and am very hapy with them. One thing I'm really happy about is that the temperatures donot change point of aim/point of impact of any of my rifles. I hope that this will be of some help. Good luck.

I've had very consistent results between lots of several of the IMR powders(4350, 3031, 4064, etc.). I've also had good consistency with both Win 760 and Hodgdon in a couple of powders. I've also had good luck with RE-15 and 19.

My go to rifle for many years has been a 7 MM Rem. A couple of years ago, I ran out of a particular lot of H870 which I had been loading for about 10 years. I bought 1 lb just to load a few for deer season, and the store did not have several pounds of the same lot. I attempted to load the same amount of powder as I had loaded previously, but surprise. It wouldn't even fit in the case. I thought I must have screwed up, so I weighed out another charge, and it wouldn't go in the case either. Hodgdon was contacted and said that some of their surplus powders could be that inconsistent. I ended up loading some with RE-19 which I was confident with. I still have that pound of H870.

My mainstay powder for a lot of years has been RL 22 in my 270 and 300 Winchester Mag. The same load in the 300, 73.5 pushing a 180 Barnes X bullet has been consistant lot to lot over the years.

I've had problems with both RL15 and RL22. With the RL15 in my .375 I had one weight of powder produce almost 2600 fps with a 300gr Nosler with no signs of pressure....a different lot of RL15 with no other change and 3 grains less powder produced almost 175 fps less velocity and I had to hit the bolt hard to open it and case head was heavily marked.

One poster mentioned RL22 and some problems awhile back....there was recall that they didn't call a recall but if you called them they told you to tale the powder back to the store where you bought it for either a refund or a new can of powder from a different lot.

I like the Reloader series but in my experience they can be tempermental.....love the accuracy and velocity when it's good.

Aren't the ALIANT RELOADER powders made by the same outfit that maked the Norma series of powders?