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Powder question for 308???
FN798
Member Posts: 17 ✭✭
I shoot 308 and load with IMR-4895, winchester cases and mostly 150gr. winchester softpoint. Have any of you shot Hogdons 4895 and
do you know the difference in the burn rates between the two. I usually see that the recipes for the amounts of powder are usually very close in powder weight.
do you know the difference in the burn rates between the two. I usually see that the recipes for the amounts of powder are usually very close in powder weight.
Comments
They are like twin brothers but not from a split egg if that makes sense.
The IMR is slightly faster and requires slightly less powder to do the same velocity but there are slight variations from batch to batch so some may be nearly the same or even further apart in loads.
If you are starting out my advise would be; which ever you find a better price on buy from the same lot in 8 pound containers and with the expected price increases as many as you can afford.
4895 is perhaps the most versatile powder in that it is not only usable in almost all calibers it is also one of the best in most calibers.
Its only short coming is being extruded (stick) making it less accurate in a progressive press where a ball equivalent would be more consistent (in load weights).
That from my experience. I currently load 308 and 8MM Mauser with it and have loaded almost everything else including 223.
It is particularly good for light loads as one can safely load 60% capacity which makes a 308 feel like a 223.(however, I recommend one always start at the start load and work down slowly checking for any over pressure signs like bulging primers)
Wulfmann
"Fools learn from their own mistakes. I learn from the mistakes of others"
Otto von Bismarck
R-15 and IMR 4064 are also good choices, IMO.
In the past you could say it was about a horse apiece. With h4895 being a smidge slower than I-4895. Therefore you could put a tad more powder and get a tad more velocity.
Anymore, the rule book is completely changed. H4895 Extreme does so much more to alleviate the temperature sensitivity. I've chrono'ed it from 90 deg in the summer down to -20 here in MN in the winter and come up with an average difference (several cartridges and loads) of less than 50 fps difference. That's a far cry from the sometimes 400 fps difference that I used to get with IMR 4895.
Now that Hodgdon owns IMR there may be something in the works to get the IMR powders to be less temp sensitive. But I can't say for sure that that is going on. I hope so. I liked the IMR powders in the summertime. Maybe I can work with them in the winter as well.
I have not seen any of the "Extreme".
Will all H-4895 be extreme from now on and is it priced the same or is their a surcharge for extremism.
Wulfmann
"Fools learn from their own mistakes. I learn from the mistakes of others"
Otto von Bismarck
It's well worth it to buy a can or two of your favorite speed and start working with it. The cool thing is working up loads in the winter and being able to shoot them in the summer. As well, of course, as having a much better idea what your trajectory is doing from hot weather to cold weather. You pretty much only have to allow for changes in atmosphere not burn rate in winter time.
JustC,
Good to hear. It was one of the most frustrating things I've dealt with with IMR. From 100-200 yds. it wasn't that big of a deal...but at 300 it was a pretty good change.
I will say though that from what I've seen it looks like the powder is something completely new. Much smaller grains and a different color. I would assume that they started with a faster burning powder (size and formula) then coated it to match 4895 burn rates. That way it always burns hot then is retarded down to the speed they want it to burn at. The formula then would help it to match pressures. I'm speculating but that's what I think is going to happen.
http://www.6mmbr.com/308Win.html
2; I buy in bulk so lets just say I have about 15k rounds to load before I get a new batch!
But, by the time I do I am hopeful they all use the new coating. I am always fearful they are also building in short shelf life even if it is a rumor it still makes me wonder.
Wulfmann
"Fools learn from their own mistakes. I learn from the mistakes of others"
Otto von Bismarck
FWIW, one of the coldest times I can ever document was in Florida. Going through Ranger school in the Florida phase at Eglin AFB, I got Hypothermia...88 deg. core temp. I was in the "comatose-dead" category. Five hours and some soup I was still 94 deg. SO I KNOW IT GETS COLD THERE![:D] Ya really gotta try the H-extremes.
Anyhow, I've had good luck with them. As usual though I've gotten great consistency from the Vihtavuori powders as well. Even if they do change more than the extremes from summer to winter.
I spent some time at FSU in Tallahassee in 69 and froze but butt off.
Look at a map in winter with temps and you will see there are differences within our state that contrast more than most of the country on many days.
The last cold day I shot was in 2001 or maybe 2002.
I have no variation in the temps I shoot right now and with 15k loads of powder for 8MM Mauser and 308 with no variation I think I am OK.
I would, in the future want the Extreme in case I move but that is 15K away today.
Wulfmann
"Fools learn from their own mistakes. I learn from the mistakes of others"
Otto von Bismarck
155 gr A-Max @ 100 yards 5 shot .383
edit Lapua brass, CCI-BR2 Primer