7mm ultra mag

[mikael]

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

[davewilson]

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.

[speedbump]

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.

[POP]

I can use some loads too with the 160 Accubonds.

[dalefarmer]

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

[dalefarmer]

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

[mrultramag]

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.