jimbires
Well-Known Member
I'm not sure if this is the article you're looking for , but have this one saved .
https://www.ballisticstudies.com/Knowledgebase/7mm+Practical.html
Anyone own a 7mm 300 Win Mag?
- Thread starter Broz
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I'm not sure if this is the article you're looking for , but have this one saved .
https://www.ballisticstudies.com/Knowledgebase/7mm+Practical.html
Yes, that is it. A wealth of information in that article! It's been my bible. Thank you so much for providing the link and thanks to the author.
I cast the chamber on my rifle and the shoulder looked pretty much like 300 Win Mag. I got a couple hundred cases on sale and necked them down, which was super-easy, as you're only going from 7.62 to 7.25.
I've had to do a lot of extrapolation with loads, because both H1000 and Retumbo are totally unavailable here now. No idea when any will come down the pipeline. So I had to use a powder I already had. I ended up using IMR 4350, which has seemed OK. Initial loads of 62 gn behind a VLD 180 yielded low-mid 28s. 63 gn behind a TMK 160 yielded about 3000 fps. I also have some slower powders like VV N165, but I'm just sticking with the 4350 until I figure out what bullet to use.
For my next loads batch, I'll use 63 and 64 gn 4350, respectively. I also borrowed 800 gn of H1000 from a friend, so I'm trying 2 batches of 5 rounds each with the VLD 180 and TMK 160.
My barrel is 26" and 1:10" twist, so the VLD 180s may not be fully stabilized, but they are shooting as well as the 160s at 100 yd. The box says I need 9", but maybe I'm getting away with a bit due to the bigger case & higher velocity. Next batch will be a bit more speed and moving the target out to 200 yd.
I also have some Sierra HPBT 180gn with BC .660, but the box says I need 8" twist, so I haven't even tried any of those.
The rifle doesn't have a very long throat, so I am seating the 180 VLDs about 0.190" shorter than the theoretical maximum with full bullet/neck contact. COAL to the tip of the 180s is 3.513. True COAL is measured with a 0.010 jump.
I cast the chamber on my rifle and the shoulder looked pretty much like 300 Win Mag. I got a couple hundred cases on sale and necked them down, which was super-easy, as you're only going from 7.62 to 7.25.
I've had to do a lot of extrapolation with loads, because both H1000 and Retumbo are totally unavailable here now. No idea when any will come down the pipeline. So I had to use a powder I already had. I ended up using IMR 4350, which has seemed OK. Initial loads of 62 gn behind a VLD 180 yielded low-mid 28s. 63 gn behind a TMK 160 yielded about 3000 fps. I also have some slower powders like VV N165, but I'm just sticking with the 4350 until I figure out what bullet to use.
For my next loads batch, I'll use 63 and 64 gn 4350, respectively. I also borrowed 800 gn of H1000 from a friend, so I'm trying 2 batches of 5 rounds each with the VLD 180 and TMK 160.
My barrel is 26" and 1:10" twist, so the VLD 180s may not be fully stabilized, but they are shooting as well as the 160s at 100 yd. The box says I need 9", but maybe I'm getting away with a bit due to the bigger case & higher velocity. Next batch will be a bit more speed and moving the target out to 200 yd.
I also have some Sierra HPBT 180gn with BC .660, but the box says I need 8" twist, so I haven't even tried any of those.
The rifle doesn't have a very long throat, so I am seating the 180 VLDs about 0.190" shorter than the theoretical maximum with full bullet/neck contact. COAL to the tip of the 180s is 3.513. True COAL is measured with a 0.010 jump.
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Someone asked me what I was using for loads with this cartridge, and thisis what I sent them, so I thought i'd add it here:
I haven't done a lot of load development with it, but I have thus far used
62gr IMR 4350 with 180gr Berger VLD
63gr IMR 4350 with 160gr Sierra TMK
64gr IMR 4350 with 145gr Speer
62gr IMR 4350 with 175gr Speer
63gr IMR 4350 with 180gr Berger VLD
71gr H1000 with 180gr Berger VLD
64gr IMR 4350 with 160gr Sierra TMK
72.5gr H1000 with 160gr Sierra TMK
barrel is 26" with 1:10" rifling. 1:8" would allow better use of the heavier bullets for long range. 28" might be better too.
If I was speccing a new barrel, I'd spec 1:8" 28"
Here's info from a guy (in Australia, I think) who made something called the 7mm Practical, which is pretty much the same thing
LOTS of good info there.
I haven't done a lot of load development with it, but I have thus far used
62gr IMR 4350 with 180gr Berger VLD
63gr IMR 4350 with 160gr Sierra TMK
64gr IMR 4350 with 145gr Speer
62gr IMR 4350 with 175gr Speer
63gr IMR 4350 with 180gr Berger VLD
71gr H1000 with 180gr Berger VLD
64gr IMR 4350 with 160gr Sierra TMK
72.5gr H1000 with 160gr Sierra TMK
barrel is 26" with 1:10" rifling. 1:8" would allow better use of the heavier bullets for long range. 28" might be better too.
If I was speccing a new barrel, I'd spec 1:8" 28"
Here's info from a guy (in Australia, I think) who made something called the 7mm Practical, which is pretty much the same thing
LOTS of good info there.
etisll40
Well-Known Member
7stw is avilable, it is only slightly less than a 300 win mag. If going 7mm and don't want to go stw, why don't you choose a case with no belt? That's probably the only thing holding the stw back from the beast it is, at least that's the only complaint I've heard?
Go with something that has manufactured brass. I've had a 7x300 variant and it's not worth the hassle of fire-forming brass. I'm on my fourth barrel and will go with the 7stw on the next barrel. Current conditions made it easier to go 7 mag because of brass availability. I live in the South and the 7mag will get me to 1200 yds on a whitetail. Good luck.
etisll40
Well-Known Member
7 mag appears to be like getting a 300 win mag, always available. I do like my stw though, unless really stretching it then 7 mag is great.
Whaler63
Member
If you're playing the BC-game w/7mm (.284) projectiles - North of 175 grains, twist rate will be your key consideration.
Nomosendero
Well-Known Member
Less available I guess you mean?
The belt is a huge problem for those who have been convinced it is a problem, for us older folks who know to headspace like any other case, not so much, even thou the belt is not needed. Funny how the 300WM still does so well !
