Powder for 175 gr Sierra Gameking 7mm mag

jbseamus83

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I did a search and didn't find anything specific to this question. I recently inherited my FIL's Savage 110 SS in 7mm mag. He also gifted me his dies, some cases, and about 200 175 gr Sierra Gamekings for it. I have used Gamekings in my .30-06, .223, and 7mm-08 and they shoot great in all of them.
This will be my first time reloading for this caliber, and am looking for advice on powders that others have been successful with. Currently, I have Varget, W760, and H4895 on hand in powders. Knowing the current market and powder availability, would any of these be reasonable to start with? I know that a slower burning powder will likely be what I am looking for, but I'm unsure if any of these might be viable or if I need to start looking for some other powders.

Thanks in advance for any suggestions.
 
Congrats on versatile cartridge.

The powders listed are too fast for a 175 grn projectile.

Hodgdon's reloading center has all the recipes for the 175 grn you'll ever want, and chances are good the rifle will shoot them accurately.

Think slower powders like 4831, 7828, 7977, RE26, RE33, etc.

Hopefully you can find an appropriate powder.
 
I've had good luck with my 116 SS 7RM with multiple bullets of around that weight with Hybrid 100V, and H1000. I'd be hesitant to use the powders you have on hand, I'd be willing to guess H4895 and Varget both burn a touch fast for a 7RM. I have no experience with W760.
 
I've had good luck with my 116 SS 7RM with multiple bullets of around that weight with Hybrid 100V, and H1000. I'd be hesitant to use the powders you have on hand, I'd be willing to guess H4895 and Varget both burn a touch fast for a 7RM. I have no experience with W760.
Thanks. That's kind of what I figured with the powders. From what I've read, there are some reduced loads using the 4895, but if I wanted a reduced load, why not just use my 7-08? From reading other forums, a lot of guys are recommending R22 or H/IMR 4831 as pretty optimal. I guess I will have to start doing some looking for some powders.
 
H4895 is a very versatile powder. You definitely won’t get max velocity out of it, but I’d bet that the Hodgdon website has data for it that will get you shooting, and likely in an accurate fashion. Slower burn rates will definitely be optimal

Edit: well, I stand corrected. No full power loads listed on the Hodgdon website for H4895. Bummer
 
Looking in a Sierra manual. IMR 4831 or H 4831 would be a good starting place. Heavy bullet in 7mm mag needs a slow powder. Don't know anything about the slow powder's they list but one I'd definitely try is R 22 start 58.8 grs max 61.1 grs. I shot a 7mm mag years ago and don't recall powders I used but the one I settled on you can't get any more, N 205. You might try R 19 but somehow I'd suspect it's just a bit fast. At the same time though, it also gives the best velocity.
 
Personally 4831 & RL19 would be the fastest burning powders i'd even consider.
H1000, Retumbo, MagPro, RL26, RL33 would be powders i'd look at.

With the faster burning powder, i'd keep an eye on percentage of case fill. You ideally want at least 85% case fill.

Something else i've found is the recoil impulse of fast vs slower powders. With the faster powders are gonna have a sharper recoil. Where as the slow powders are gonna feel more of a push. A fast hard push, but still feels less harsh.
 
If you have an iPhone try this. I loaded it a long time ago but recently tested it and found its pretty good for powder selection.

 
Last time a loaded for a 7mm Rem Mag, a few years back, I used both the Sierra 160SBT and the 175SBT. I used R26 with the 160 ( 3100 easy) and R33 with the 175 (solid 3000) Fed 215 Magnum Primer, Winchester cases. BUT...I used a 26" barrel. Theoretically you could knock off 50fps for both loads, but maybe not...depends on the rifle. Both are good, tough bullets, perfect for the 7mm Rem Mag IMHO.
 
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Last time a loaded for a 7mm Rem Mag, a few years back, I used both the Sierra 160SBT and the 175SBT. I used R26 with the 160 ( 3100 easy) and R33 with the 175 (solid 3000) Fed 215 Magnum Primer, Winchester cases. BUT...I used a 26" barrel. Theoretically you could knock off 50fps for both loads, but maybe not...depends on the rifle. Both are good, tough bullets, perfect for the 7mm Rem Mag IMHO.
How far are you seating off the lands? I have been trying Sierra bullets but getting poor results.
 
I can personally recommend Reloader 23, 25, 26.
Performance will be meager with any powder that has a faster burn rate than R-19.
7828 is a good one too, if you can get it.....
I use R-23.
 
How far are you seating off the lands? I have been trying Sierra bullets but getting poor results.
Start with 0.020" off the lands.
I'd do 6 cartridges each at 0.020", 0.030", and 0.040". Shoot 2 groups of 3, to take any shooter error out of it.

Sierra's are fairly jump tollerant.

Check your measurement with the length of your magazine.
If it's too long it turns your rifle into a single shot. :oops:
 
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Reloader 22 has been my powder of choice for the 7mm Remington Magnum for a long time. Good velocity and accuracy. Any of the slower burning powders should do well. My 7mm's have shot the 175 Sierra and 175 Nosler Partition well.

Last year I used the 160 grain Sierra SPBT Gameking from my 7mm Remington Magnum, Ruger Number One to take mule deer & antelope. Accurate and lethal. Recovered the bullet from the mule deer, it was well expanded and caught by the off-side hide. I would expect more penetration from the 175 grain version.

hgWXWNgl.jpg


Some years back I shot a big 6x6 bull elk with a 175 grain Nosler Partition. Right through the chest, in and out. Trashed the lungs and top of the heart. Bull staggered about 6 more steps and collapsed. I thought that was pretty doggone excellent performance. Shot was about 180 yards as I recall.

I'm running out of RL-22, and haven't been able to find more locally. Am trying IMR 8133 instead, and so far the results are good, but I've been using 160's, not 175's yet.

Regards, Guy
 
Reloader 22 has been my powder of choice for the 7mm Remington Magnum for a long time. Good velocity and accuracy. Any of the slower burning powders should do well. My 7mm's have shot the 175 Sierra and 175 Nosler Partition well.

Last year I used the 160 grain Sierra SPBT Gameking from my 7mm Remington Magnum, Ruger Number One to take mule deer & antelope. Accurate and lethal. Recovered the bullet from the mule deer, it was well expanded and caught by the off-side hide. I would expect more penetration from the 175 grain version.

hgWXWNgl.jpg


Some years back I shot a big 6x6 bull elk with a 175 grain Nosler Partition. Right through the chest, in and out. Trashed the lungs and top of the heart. Bull staggered about 6 more steps and collapsed. I thought that was pretty doggone excellent performance. Shot was about 180 yards as I recall.

I'm running out of RL-22, and haven't been able to find more locally. Am trying IMR 8133 instead, and so far the results are good, but I've been using 160's, not 175's yet.

Regards, Guy
Good info. I have also always had spectacular performance with gamekings. I've used them in .223 to bring down 225 lb hogs in Texas, 7mm-08 and .30-06 on whitetails.
I have been looking all around where I live here in UT and haven't been able to find R22, 23, any of the 4831.

If anyone has a recommendation on where to look online or in person, I would love to get my hands on even 1 lb of any of these.
 
Powder seems to be creeping back into inventory in the local sporting goods stores here in central Washington - but slowly and haphazardly. Glad I was pretty well stocked with components before this danged shortage.

Except for RL-22... That I had less than a half pound left. Sigh...

Guy
 
Hey Seamus, I see some R33 and R26 over on Gunbroker. Expensive. I also saw some 7828 over on KSL Classifieds. 7828 has been good for me too, even in the 7mm RUM. Good luck to you Pard.
 
Keep checking your local shops. Powder has been hit & miss here in PA. If your patient, and check around you can uusually find what you want within a couple of weeks.
Primers are a different story!
 
Ok, so I'm still having trouble finding the powders that have been mentioned here so far, but I can get my hands on some Vihtavuori N170. I have found load data for the 7mm mag on their website and, while it's not going to push a 175 gr too fast, it is a loadable powder for this caliber. Anyone have experience with this powder in the 7 mag?
 

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