7mm ultra mag

mikael

Active Member
Joined
Jun 15, 2005
Messages
42
hi im just builth an 7mm ultra vith 28" barrel which powder are best four that caliber im from sweden so i can geth r-25 h-1000 imr 7828 and v-170 bullet 140-160gr
 
not familiar with the 170 but the other 3 will work fine.try em one at a time with the bullets you intend to use and your gun will tell you which is best.my only advice would be to work towards a max load very slowly. a 7UM is quite overbore and pressures can peak real quick.
 
Mikael, like Dave said, start with lower powder charges & work toward maximums slowly, as pressure DOES peak suddenly with most powders in this caliber.

With heavier bullets (+160gr), a powder suitable for a 50BMG might be in order. Mine likes 5010 surplus powder better than anything. Since you're a Scandanavian, Vihtavouri makes some good ones that could be the ticket. I've been curious about 20N29 & one other one I can't remember at the moment. Something on the burn chart around Retumbo/ H1000/ 5010 should get you close. Best of luck.
 
I have used up to 93.5 grains of RL-25 with 160 Accubonds, Remington cases and Fed GM215M primers, and didn't see any pressure signs but that is 2 grains higher then any documented loads I have found. I dropped to 92.5 just to be safe. I don't know what speed I'm getting but I have to use 38 clicks at 675 yards with a 100 yard zero.
I also received these loads from Alliant, they said they didn't have any of thier own data but to use these.

7 mm Rem Ultra
Hornady Data


139 gr SP
RL 22 start 74.2 grs @ 3000 fps max 90.4 grs @ 3400 fps

154 gr RN
RL 22 start 74.5 grs @ 2900 fps max 86.1 grs @ 3250 fps
RL 25 start 83.9 grs @ 2900 fps max 93.7 grs @ 3300 fps

162 gr BTSP
RL 22 start 75.8 grs @ 2900 fps max 85.9 grs @ 3250 fps
RL 25 start 83.2 grs @ 2900 fps max 91.3 grs @ 3300 fps

175 gr RN
RL 22 start 71.7 grs @ 2700 fps max 82.1 grs @ 3050 fps
RL 25 start 77.7 grs @ 2700 fps max 88.6 grs @ 3100 fps
 
Also received these from Alliant.

7mm Rem Ultra Mag
Swift Bullet Data

150 gr Scirocco
RL 22 start 78.1 grs @ 2969 fps max 84 grs @ 3196 fps
RL 25 start 82.3 grs @ 2999 fps max 88.5 grs @ 3181 fps

140 gr A Frame
RL 22 start 79 grs @ 3093 fps max 85 grs @ 3285 fps
RL 25 start 86.5 grs @ 3153 fps max 93 grs @ 3355 fps

160 gr A Frame
RL 22 start 77.2 grs @ 2907 fps max 83 grs @ 3107 fps
RL 25 start 80 grs @ 2903 fps max 86 grs @ 3057 fps

175 gr A Frame
RL 22 start 74.4 grs @ 2766 fps max 80 grs @ 2968 fps
RL 25 start 76.3 grs @ 2757 fps max 82 grs @ 2904 fps
 
my best luck has been with RL25 so far. Thats not saying other powders aren't as good or better. RL25 has delivered top velocity and accuracy for me but I have done extremely limited load development on my 7 rum. I lucked into a load with the 150 partition and just went hunting and have not bothered with much else.
 
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