Home Forums Reloading Big Game Rifles 300 Wing Mag IMR 7828 opinions

I'm using 180 Accubonds and have run a lot of tests using IMR 4350 H 4831 IMR 7828 and H 1000. I've been doing my tests from 55 - 65 degrees. I wanted to do my testing in temps from 30 -50 degrees but our weather went from sub 30's right to 60's. Unreal. I've also did a lot of off the lands testing ranging from .03 - .08.

IMR 7828 is winning out in my barrel. 76 grains with .03 of lands producing .637 in 3 shot groups and .04 producing .402 3 shot groups with average speed of 3110. SD has ranged from 3104 to 3122 but enough testing on this yet. I going to try .035 of the lands and change powder by .2 grain each way to see if I can get them any tighter but hard to beat .402 inch groups.

My questions/concerns my hunting temps will be mainly from 20 - 40 degrees. I have no knowledge on IMR 7828 temperature sensitivity. 50 - 70 fps loss is not a big deal in inches out to 400 but a little more from 400 - 600. I'm more concerned about how my groups will open up with that decrease in velocity.

Any body have any experience or educated guesses how many fps I might lose and how much groups might open up? Also I could be hunting at temps around 0 (not very likely) and if that happens I'm guessing I would have to limit my shots to 300 yards but just guessing. I will be able to do this testing next fall/winter but I have a NM elk hunt in mid October so asking because of this hunt.

No tests on 7828. I've used H4350 when it was around 0, no sweat. I will say that I have used a lot of 7828 in handloads of other rounds with no issues, just not that cold nor overly hot temps either.I can remember when it was the factory powder (no canister) used in the 7mm Rem Mag and believe you me, people used that round and factory ammo all over the world! So, I would load up my two best loads using both 7828 and either of the Hodgdon Extremes. When it got cold I'd just check my zero and check them with one of the very portable ( even on a hunting trip) Chronies or similar. Same when it got hot.
Myself, if I have "any doubts" I use one of the known/tested Temp Stable powders. We are blessed with many nowadays. I have used a 300WM with 76gr R22 behind the older Barnes 180XBT, going 3100 in Namibia...20 degs at night, 120 degrees by Noon! No problems at all. Yet, I had a load of 61gr R22/280AI/150NBT work swell here in Utah but stick the bolt in Texas in 90deg February. I do think that case size matters, so needs testing, research.
That's the best I can do for you Pard but...when in doubt...go with what has really been tested/proven stable I say!

7828(ssc) is about the only powder I use in my .300. I have found it to be excellent with both 150 and 180 grain bullets.(Particularly 80gr under a 150gr Speer).

My best groups so far with 150's have been with RL-22 which is pretty close to MRP. I have RL-23, just haven't tried it.

I've read good stuff about RL-26 with heavier bullets.

7828 is a great powder, just haven't used it that much.

DF

I used IMR 7828 in my 280 Rem many moons ago with no problems. Target practice conditions ranged from a low of 30 in late winter to a high of 95 in mid Summer. Didn't shoot too much at 95 degrees tho...LOL I never had any problems with accuracy or pressure. I quit using it because I "found" RL-22 and like it a little better. A few weeks back I found a deal on IMR 7828, 15 dollars a pound, and bought all they had, about a dozen.. For 15 dollars per, I'm gonna be shooting IMR-7828 again.

I know the above doesn't really answer any of your questions but if a 20 degree swing in temps, 20-40 degrees is all you are going to encounter, I would put that "worry" to bed. Good luck...

I've used RL-22 as my go-to powder in the 300 forever, but 7828 virtually duplicates it in performance.............use the SS version & it meters better through a powder measure as well.

If I were going to work up a new load today, it would likely be with RL-26 because of the temp stability & I would expect performance to maybe be a tad better than '22 or 7828 as a bonus.

But you won't go wrong with 7828.

MM

I’ve had very good luck with 7828 in the 300 WM!

I bought a # of 7828 for $15 3 weeks ago from a dealer at the Gunshow in Greenville with the intent of loading 300 WM 165 partitions or 165 TTSX.

I am not sure about temperatures, but I use 75 Grains of IMR 7828 , pushing 165 Grain Swift Scirocco II's in my 300 Winchester. I get great groups. I load to standard COAL. This load shot so well in both 300 Win Mags I have owned that I have not tried anything else other than some Federal 150 Grain factory loads. I do not really shoot when it is super hot out, but I have shot it in low 30's to mid 80's and never had a problem.

Tag for future reference, need to try some soon.