7 mm SHERMAN SHORTMAG vs 7 SAUM

[Stuntman Jeff]

1cpalmer,
Thank you, thank you, thank you!! This is some great detail and will help tremendously.
Jeff

 

[Copper Basin]

1cpalmer,
Thank you, thank you, thank you!! This is some great detail and will help tremendously.
Jeff

It is what worked in the rifle I built. I have 3 more getting ready to go. Start low and work up.

 

[b6graham]

i see a lot of RL26, H1000, N565

how about N570? (and N560 as a fireform/break in load)

going 26" bartlein M24 carbon, 8 twist
have a stockpile of 195 EOL

 

[UCzO___]

Has anyone used Gordon's Reloading tool to analyze their 7SS loads? Anyone want to share their Cartridge/Chamber data for the tool?

Thanks!

 

[lancetkenyon]

i see a lot of RL26, H1000, N565

how about N570? (and N560 as a fireform/break in load)

going 26" bartlein M24 carbon, 8 twist
have a stockpile of 195 EOL

N570 was too bulky for my 7SS w. 184 Hyb. I couldn't get enough in the case to pressure out or get the speeds I wanted in a SA fed by a WSM mag.

My 7SS is a 24" 1:8.4" Proof CF.
I have been running a max load of N565 with the 184 @ 2838fps. 2855fps was max where I got my first sign of pressure, and powder was quite compressed too.

I also have a super accurate moderate load with H1000 @ 2788fps. Got up to 2812, but was out of case space. No pressure.
RL23 got me to 2800 too. But was maxed out there with first sign of pressure.

Being from AZ where hunting/shooting temps can be anywhere from 4° to 110+°, and with my past experience with the 84°+ pressure spike, I always steer away from RL26. Well, yesterday, I decided to try RL26 as a "late season" option. Glad I did. While my shooting was done yesterday from 75°-90°, I was pleasantly surprised. I got the same 184 Hyb up to 2933fps with no pressure as my last load test (90° when I shot them). I could probably go .5-1gr more at least, but Summer is approaching and very soon, even 85° will be unavailable until late Sept, even at sun-up. I might revisit RL26 in the fall when it cools down again.

This was my 3 shot group at 2902fps w. RL26 and the 184 Hyb @ 2.180" CBTO (where my rifle likes them seated).
2902fps, ES 7.

 

[UCzO___]

N570 was too bulky for my 7SS w. 184 Hyb. I couldn't get enough in the case to pressure out or get the speeds I wanted in a SA fed by a WSM mag.

My 7SS is a 24" 1:8.4" Proof CF.
I have been running a max load of N565 with the 184 @ 2838fps. 2855fps was max where I got my first sign of pressure, and powder was quite compressed too.

I also have a super accurate moderate load with H1000 @ 2788fps. Got up to 2812, but was out of case space. No pressure.
RL23 got me to 2800 too. But was maxed out there with first sign of pressure.

Being from AZ where hunting/shooting temps can be anywhere from 4° to 110+°, and with my past experience with the 84°+ pressure spike, I always steer away from RL26. Well, yesterday, I decided to try RL26 as a "late season" option. Glad I did. While my shooting was done yesterday from 75°-90°, I was pleasantly surprised. I got the same 184 Hyb up to 2933fps with no pressure as my last load test (90° when I shot them). I could probably go .5-1gr more at least, but Summer is approaching and very soon, even 85° will be unavailable until late Sept, even at sun-up. I might revisit RL26 in the fall when it cools down again.

This was my 3 shot group at 2902fps w. RL26 and the 184 Hyb @ 2.180" CBTO (where my rifle likes them seated).
2902fps, ES 7.
View attachment 367569

Do you mind giving your top charge weight. I ask because I opened my first can of Unicorn tears last week and my velocities were not what I was expecting.
TiA

 

[lancetkenyon]

I was in the middle of the range of the other 180-185 loads using RL26.

 

[Gstew1930]

It looks like SAC released a magnum seating die. Would the .550 work for the SS cartridges or would it need a .555?

 

[highdrum]

It looks like SAC released a magnum seating die. Would the .550 work for the SS cartridges or would it need a .555?

Measure the base and shoulder diameter of your sized cartridge, call SAC with that information and they will let you know.

 

[Gstew1930]

Measure the base and shoulder diameter of your sized cartridge, call SAC with that information and they will let you know.

Yeah I just got off the phone with them. The saum die will work when it's releases

 

[KH_Outdoors]

Fantastic

 

[jpgolffl]

This is a heck of a thread! I've dug but can't find a for sure answer- If I want to do a 7SS on a desert tech srs, is there a mag that can be used? Their long action mag says it's compatible with 300wm/338LM/7WSM. I'm new to desert tech but that's a wide range of cases for a mag. If 7wsm works 7SS should work shouldn't it?

 

[Gstew1930]

This is a heck of a thread! I've dug but can't find a for sure answer- If I want to do a 7SS on a desert tech srs, is there a mag that can be used? Their long action mag says it's compatible with 300wm/338LM/7WSM. I'm new to desert tech but that's a wide range of cases for a mag. If 7wsm works 7SS should work shouldn't it?

Accurate mag will work just fine, you may have to adjust the feed lips a hair but it will work

 

[elkaholic]

This is a heck of a thread! I've dug but can't find a for sure answer- If I want to do a 7SS on a desert tech srs, is there a mag that can be used? Their long action mag says it's compatible with 300wm/338LM/7WSM. I'm new to desert tech but that's a wide range of cases for a mag. If 7wsm works 7SS should work shouldn't it?

yes, they have been built