New IMR Powders???????????

[Shynloco]

Ok Guys,
What's up with all these new IMR powders or at least new labels? I saw a bunch of them today at my local Gun Shop and was trying to figure out why these new labels/powders were developed? I mean are they better than what we've been using or are they "caliber or load specific" or something like that? I'd like to hear the rationale behind the reasoning so this old dinosaur can move into the "new age of powders." Thx.

Alex

 

[jonbearman]

It is supposed to have a copper eliminator additive, better load density, and good temperature insensitivity. That is all I know but cant wait to try it if the weather ever improves here in new York state. I read somewhere that they are not going to eliminate powders from their product line but time will tell.

 

[flatlander]

Get a copy of the latest Hodgdon loading manual, the one with a photo of the three new IMR Enduron powders on the cover. There are three separate articles - one on each of the new powders - written by three respected authors. Lots of to-the-point info in the articles, and there's also quite a bit of load data for all three of them included in the regular load data section of the manual.

So far, 4451 is the only one I've tried, and I've found it to be much less temp sensitive than IMR4007, which has been discontinued. I was shooting loads for a 6.5x47 competition rifle with 123gr bullets using both powders that had been chronographed on 45*F & 81*F days - the 4007 loads were nearly 50fps faster on the 81* day, while 4451's velocity was within 3fps. In my experience in 6x47, 6.5x47, & 260 Improved 30*, 4451 is similar to IMR4350.

 

[padom]

I have seen some pretty good testing of the new IMR 4166 powder with .308 bullets. From what I've seen its right on par with IMR4064. 41.8 was 2606 and 42.2g was 2653 in lapua cases with 175smk and was shooting small holes. Here's some info from a member on another forum that did the testing.

Remington 700 Varmint .308 26" / 65F

40.9gr 2557.4
41.4gr 2593.2
41.8gr 2606.8
42.2gr 2653
42.7gr 2668
43.1gr 2698.6 <---- MAX LOAD
43.5gr 2723.8 <---- ABOVE MAX
44.0gr 2734.4 <---- "
44.4gr 2757.0 <---- "