I'm starting some new loads with my 7mmRemMag using 160gr Partitions and Rem brass.

Which powder would you choose (assuming they are available)?

Right now I know I can get Win 780, Retumbo, Ramshot Magnum, and 4831.

I know 4831 so are there any issues with the other three? Particularly temp sensitivity.

Great topic for me. I just started loading for a new 7mmRemMag. I received 200 rounds of Hornady 120gr from a friend so I'm breaking in my barrel with those.

So far I used H4350 with less than stellar results. I just loaded 20 rds up using W760. I am hoping to give them a shot this weekend. WIll let you know.

I've never had luck with 4350 (of any type) in my 7mmMag.

I used Ramshot hunter once and had delay fires in sub zero temps so I'm pretty leery of a new things.

My favorite powder for the 7 RM is IMR7828. I works great with most bullet weights (140 thru 175).

I have a 7mag Weatherby Vangaurd and have tested H 4831SC, IMR 4350, RL-19, Rl-22, and Win780. Of the five H4831 may have not been the fastest but was far more accurate from my rifle so thats what I stuck with....I was shooting 160 grn Nos Accubonds.

rl22

quote:

rl22

Or better yet MRP

I use a load of 60.0 gr. of IMR4350 using the 160 gr. Partition. I also use Remington brass and Federal 215 primers. This load shots very well in 2 different 7mm Remington Mags. It has worked well on African game, Mule Deer, Blacktail Deer, and Bears.

Greg

Rumor has it that Supreme 780 is very similar to MRP (unless I miss read it may be the same).

So here's the question. Is RL-22 temp sensitive?

I also here that lot to lot variations are fairly extreme for RL-22. I'm not against extruded powder since I'm using 4350 in my 300WSM.

IMR4350 worked best for me.

Two powders work very well in my 7mm Mag, H-4831SC and RL-22. They are all I've ever used come to think about it.

Well after looking at some other info, I've decided that I don't want RL-22 due to the temp sensitivity and lot to lot variations. It looks like a fantastic powder but the extreme temp swings locally make me leery.

It looks like Retumbo might be my choice because it seems to be temp insensitive and fairly consistent between lots.

I've tried IMR4350 and XMR4350 in 139 and 154 bullets and had sub-par performance.

quote:

I've decided that I don't want RL-22 due to the temp sensitivity and lot to lot variations

I will admit to having seen a several grain varition between my first lott of rl22 and the next. However the last 2 lotts have been gr for gr. Unless you are going to shoot your 7mag a heck of a lot if the lott variations worry you buy 5# that over 2200rds in a 7mag.

As to temp. I've read all the press usually by one powder firm trying to hype their own. Hodgdon had a table on their web site a couple years back trying to show how great their extreme powders were as to temp. In that table RL22 had a 75fps variation over a 125deg temp spread. http://www.ask.com/bar?q=hodgd...3D&tsp=1256150099610 For some reason I can't get it to link to the table so you will need to click on "take the extreme tour"
Any powder loaded to a max load at a low temp and then taken to high temp can cause issues.

I have a wildcat 280PDK looks like an improved 7Gibbs I load it to 7mag velocity. A load worked up at around 70-80 deg has worked for me from sea level to 12,000' and from -10 to 114. RL 22 is my go to powder for my wildcat as well as 7mag and 7stw.

H-4831 OR RL-22

IMR 7828 for bullets 160 grns. or heavier, IMR4831 for the lighter weights have worked best for me.

Has anyone tried WC860 (surplus BMG) powder in this cartridge?

quote:

Originally posted by jpl:
Has anyone tried WC860 (surplus BMG) powder in this cartridge?

Tried 5010 and 5020 50 BMG surplus and could not achieve reasonable velocities before I ran out of powder room ,and got a whole bunch of unburned powder. While discussing this with a long time reloader he said"perhaps you're lucky it did not all burn. If it did you might find that you had too much." Later, experimenting with duplex loads I found out that he may have been correct. roger

I tried 5010 in a 7stw with 160s and found while I had great accuracy it was very slow. Velocities under 7mag levels.

I've found RL-22 excellent for both 140 and 160 gr. bullets in the 7mm Remington Magnum. I use Federal 210M (large rifle as opposed to large rifle magnum) primers in mine.

Maybe RL-22 is temperature sensitive but I found that there was a 2 to 3 grain (maybe a bit more) range in powder increments where the accuracy was the same and the bullets hit in the same place. If you kept your load toward the middle of that range temperature sensitivity shouldn't be an issue (though I doubt it's really an issue anyway).

RL-22, H4831 and IMR 7828 would be excellent starting powders.

Damn! Looks like I'm the only one burning H1000. My 7 mag loves it with Sierra 175gr.

RL 19, RL-22, H1000

I've used a few different powders and had best results across the board using Retumbo...recently bought five pounds of it!

My 7mm RM loves Retumbo in 160 grs and above. 150 and below I like RL 22.

quote:

Originally posted by BigChev4x4:
I use a load of 60.0 gr. of IMR4350 using the 160 gr. Partition. I also use Remington brass and Federal 215 primers. This load shots very well in 2 different 7mm Remington Mags. It has worked well on African game, Mule Deer, Blacktail Deer, and Bears.

Greg

Same load here except for Federal brass

quote:

Originally posted by BigChev4x4:
I use a load of 60.0 gr. of IMR4350 using the 160 gr. Partition. I also use Remington brass and Federal 215 primers. This load shots very well in 2 different 7mm Remington Mags. It has worked well on African game, Mule Deer, Blacktail Deer, and Bears.

Greg

I have shot this load in my 24" stainless 700 with a 160 Accubond. It chronyed just over 3000........while 69grs of Rel22 pushes a 140 TSX over 3300.

quote:

Originally posted by gwindrider1:
IMR 7828 for bullets 160 grns. or heavier, IMR4831 for the lighter weights have worked best for me.

Me too. I like H4831sc as well, IMR4831 too, but I get just as good accuracy but upto 100fps more vel. w/ IMR7828.

I've found the 7m/m Rem mag to be one of those "funky" cartridges that might do as well on 4350 as it will with 7828. It is also a potent hunting cartridge when the proper selections are made. That said, it and the 257 Roberts are my favorite sub 30 calibre hunting choices. My model 70 does well with N-160 and 160 grain partition bullets producing 3050 f/s. I can get another 100f/s with slower powders, but the accuracy necessary for long range wasn't there.

the powder mfgr now lists the new RL-17 at a top performer for the 7mm Rem Mag in some bullet weights.
That seems very wierd when examined next to
the RL-19 and RL-22 loads but the benchrest guys
are ranting and raving about it being in a new
revolutionary technology for higher velocities
with the 6mm cartridge. The other new technology powder is the H100V Hybred ( or something like that) Modern science ought
to give us something better every now and then.

I've had the best luck with RL-25 and IMR 7828 in the 7mm rem mag. I've tried 4350 and 4831, but in my opinion they're too fast burning for this cartridge. I used to use RL-22 but tried RL-25 and now prefer it.