7mm Magnum powder choices

thatmikeguy

thatmikeguy

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Merry Christmas guys. I hope your hunting is going well.
I just bought my self a 7mm Mag. I've never owned a 7mm before. I have 2 powders which appear to be good choices, imr 4831 and imr 4350. (Which I also use in my 243) I will be loading Nosler solid base 150 grain bullets. I would like to know which powder to start with. I definitely realize that every rifle is different and I have to try it etc. I would like to know if there is a trend for the 7 mag preferring one over the other. The charge weights and velocities are very similar. The nosler manual lists a most accurate load with a minimum charge of 4831 and a max charge of 4350 which means the 4350 would have the speed advantage but that is if it works that way in my rifle which is a T3X laminate stainless.
 
IMR 7828--Norma MRP-RL-22 are also good choices. Most slow burners on the burn rate chart between the various 4350's and Retumbo would work good. JMO
 
If one can find it, Magpro was supposed to be the powder for the 7mm Rem Mag and 160 gr bullets.

Use the one that produces the best groups in your rifle.
While velocity is ###y, accuracy builds confidence in putting the bullet in the vitals for quick, clean kills.

While I strive for a good balance of both, accuracy will determine the final load over velocity every time for me.
 
I load h1000 on 162 grain bullets. I also have imr8133 and imr4831 on the shelf to experiment with. From the reading i have done 4350 powders wont provide a great case fill ratio. Seem a bit fast of a powder for it.
 
The 4831 should serve you well in the 7mm rem mag I would think
tough finding other powders right now for anything close to a reasonable price.
I know my rifle likes the 160 nosler and it also likes the 174 accubond LR.
Had a friend load me up some rounds with the 4831sc as he has years of experience over my novice-ness
I was quite happy with the results though i don't have the load data handy
 
BlackRam said:
If one can find it, Magpro was supposed to be the powder for the 7mm Rem Mag and 160 gr bullets.

Use the one that produces the best groups in your rifle.
While velocity is ###y, accuracy builds confidence in putting the bullet in the vitals for quick, clean kills.

While I strive for a good balance of both, accuracy will determine the final load over velocity every time for me.
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I also strive for accuracy and velocity. I'm willing to lose a little speed for accuracy but not too much. I dont want the caliber I shoot to become the next smaller caliber.
 
45ACPKING said:
The 4831 should serve you well in the 7mm rem mag I would think
tough finding other powders right now for anything close to a reasonable price.
I know my rifle likes the 160 nosler and it also likes the 174 accubond LR.
Had a friend load me up some rounds with the 4831sc as he has years of experience over my novice-ness
I was quite happy with the results though i don't have the load data handy
Click to expand...

Back when prices were reasonable and powder wasnt near as scarce, I wouldn't mind picking up extra of this or that but these days not so much. H1000 and Retumbo or Alliant Reloader powder seems to be popular for 7mm magnum but I dont know if I could find them if I wanted to and im not very interested in paying for them either.
 
I have burned a lot of IMR 4831 in 7mm Rem Mags over the years.
It seems very suited to 140/150 grain bullet in the big 7

With your 150's, start at 63 grains and work up in ½ grain increments
You should top out at 65/66 grains.

I have always had stellar accuracy with 150 Accubonds and IMR 4831

Just as an aside, I won sporter class at Burns Lake 1000 yard match
with the 7mm Rem Mag, shooting the 150 Ballistic Tip and 65 grains
of IMR 4831. Dave.
 
Eagleye said:
I have burned a lot of IMR 4831 in 7mm Rem Mags over the years.
It seems very suited to 140/150 grain bullet in the big 7

With your 150's, start at 63 grains and work up in ½ grain increments
You should top out at 65/66 grains.

I have always had stellar accuracy with 150 Accubonds and IMR 4831

Just as an aside, I won sporter class at Burns Lake 1000 yard match
with the 7mm Rem Mag, shooting the 150 Ballistic Tip and 65 grains
of IMR 4831. Dave.
Click to expand...

That's excellent. Thanks for that.
 
When playing with a 7 Rem, your chronograph is definitely your friend. If ever there was a cartridge that the book speeds don't mean anything that's the one. I'm not saying you won't get book velocities because you might; but don't be too shocked if you don't get within 2 miles of it. There doesn't seem to be a lot of rhyme or reason to it either.

There was a period of time when I loaded for several friends who shot 7 Rems. I worked up the load in the first friend's rifle with 4350 and 154 Hornadys with great results, and since it proved to safe in the other's they all got the same load. I never bothered to tell the others that in their rifles "The Load" made a 30-06 with blue box Federals seem like a speed demon. Since I didn't want to contribute to someone getting into a long term relationship with 30-06s and factory loads or even worse finger-banging a .308, I just sort of just kept that info to myself. Just throwing it out there; since you don't want to end up with the next smaller caliber.

For what its worth; I load my Kimber 7 Rem with 7828 and 150 Ballistic Tips and 160 Accubonds. That one isn't afraid of a chronograph. :)
 
I have found H4831SC to be an excellent powder in the four 7Mm Rem Mags I have loaded for. Great accuracy with 160/175 Partitions and 160 Accubonds. I have found the velocity to be very consistent as well.
 
My present 7mm Rem Mag [700 BDL, 24"] is a very accurate rifle, and
the chronograph shows pleasing results as well
140 grain Partition - 3280
150 grain Scirocco II - 3140
160 Accubond - 3060

Dave.
 
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Dogleg said:
When playing with a 7 Rem, your chronograph is definitely your friend. If ever there was a cartridge that the book speeds don't mean anything that's the one. I'm not saying you won't get book velocities because you might; but don't be too shocked if you don't get within 2 miles of it. There doesn't seem to be a lot of rhyme or reason to it either.

There was a period of time when I loaded for several friends who shot 7 Rems. I worked up the load in the first friend's rifle with 4350 and 154 Hornadys with great results, and since it proved to safe in the other's they all got the same load. I never bothered to tell the others that in their rifles "The Load" made a 30-06 with blue box Federals seem like a speed demon. Since I didn't want to contribute to someone getting into a long term relationship with 30-06s and factory loads or even worse finger-banging a .308, I just sort of just kept that info to myself. Just throwing it out there; since you don't want to end up with the next smaller caliber.

For what its worth; I load my Kimber 7 Rem with 7828 and 150 Ballistic Tips and 160 Accubonds. That one isn't afraid of a chronograph. :)
Click to expand...

In my experience as a reloader (about 20 year now) if I'm not getting close to top speed for the caliber and components I have then I need to switch powders.
 
IMR 4350 with 160gr Accu-Bonds N165 with 139gr SP Hornadys ................although it was 3/4 MOA with 160gr Accu-Bonds as well not as tight as IMR4350 in my gun
 
thatmikeguy said:
In my experience as a reloader (about 20 year now) if I'm not getting close to top speed for the caliber and components I have then I need to switch powders.
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Well; you're not wrong. I only have 40 years of reloading behind me, which is sort of sad in a way. Where did those years go? Don't know; but they sure went fast.

I think it was about '88 when we started playing with STWs. It wasn't like it was something new except the name; there just weren't any powders around to make it work before that. The Rem mag made its reputation with 7828 long before we we could get it and it basically stunk without it or equivilents. Either way, the STWs ate the Rem alive. It was a different era though, every gunwriter in the world said you couldn't match Weatherbys factory velocities with handloads.

I'm not sure if I have a point, except that if you think you are going to get speeds out of 4350 you better be counting on some luck. I wish you good luck; and definitely dont wish you any harm.
 
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