7 Sherman Short Mag

[RampedRaptor]

Hello everyone,

Looking at getting a barrel chambered in 7 SS and thought I would ask for your insight before I fully committed.

Uses:
Paper/steel plinker 235 yds to 1 mile.

Rifle:
28-30” Barrel on a short action

Reloading:
300 saum brass
180 eld-m or 180gr Hybrid
Powder- temp stability is a primary. Maybe 4831sc or Reloader 23?

Concerns:
Not inherently accurate and may be finicky with tuning. Extra work and money spent wildcating when a 7 Saum with the bullet stuffed in the case would do the same thing.

Thoughts:
My concerns are only because it’s new and I haven't seen anyone win 1000yd BR with it yet. I’ve always been attracted to efficient cartridges and the 7sherman short mag seems great on paper.

Any insight or experiences that have not already been documented elsewhere would be greatly appreciated


Thanks,
RR

 

[LA50SHOOTER]

My perception is it should be a good proposition if you like having something different & obtaining pretty much the same results as a 7 WSM.
Nothing wrong with a unique design. - I think its going to be hard to top the 300 WSM though in 1000 yd. BR.

 

[Ringostar]

What is the difference in length between the SS and a SAUM case?

 

[RampedRaptor]

“The SS is .075" shorter oal. It is .095" shorter at the neck shoulder junction which determines where proper bullet seating depth starts. It has a .020" longer neck than the saum. It has a 40 degree shoulder and less body taper keeping case stretching to a minimum.” R. Sherman

 

[Ringostar]

Thanks

 

[sdean]

I have a shortened 6.5 40* Rsaum. Probably not worth the work. I just can't see any advantage to shorten a 7MM. At the most go to a 35* shoulder.

 

[RampedRaptor]

It’s probably follish but I’m going to go ahead and get a barrel chambered in it. Since there wasn't anyone who commented “they’ve been there done that” I can be the first to report back.

It’s going to be awhile before dies and barrel are ready but once they are and I have some meaningful data, I’ll report back as long as someone else hasn’t already.

Thanks to those that did respond via message or reply!

 

[SurgeonCO]

I’m planning on doing one when the brass and reamers are available. 8 twist brux waiting for it. I talked to a fellow shooter that has the 6.5ss on a hunting rifle. Says it’s a hammer

 

[Ringostar]

Does anyone know the water case capacity?

 

[RampedRaptor]

Sadly I do not. I will say it’s almost the same as the saum. Rich was nice enough to send me 2 cases to mock up and I’m very excited now that I have a formed case in hand. The case looks perfect. I will say I would of probably pushed the shoulder back 10 thou more or so. Initial testing shows the pressure ring on the 180eld just below the neck/shoulder junction. I will look at it more as I as running late to work tonight.

 

[dkhunt14]

Sadly I do not. I will say it’s almost the same as the saum. Rich was nice enough to send me 2 cases to mock up and I’m very excited now that I have a formed case in hand. The case looks perfect. I will say I would of probably pushed the shoulder back 10 thou more or so. Initial testing shows the pressure ring on the 180eld just below the neck/shoulder junction. I will look at it more as I as running late to work tonight.

Thats nothing a longer throated reamer or a throater won't fix. Matt

 

[RampedRaptor]

Thats nothing a longer throated reamer or a throater won't fix. Matt

Sadly I’m maxed out on magazine length.

 

[dkhunt14]

Sadly I’m maxed out on magazine length.

In a long action? Matt

 

[RampedRaptor]

In a long action? Matt

Short. 2.96

 

[dragman]

Sadly I’m maxed out on magazine length.

Why limit yourself with a magazine, slap a single shot follower in that thing and STRETCH it out!!!

 

[RampedRaptor]

Why limit yourself with a magazine, slap a single shot follower in that thing and STRETCH it out!!!

Because the chase for “stretching” something out never ends. If I can’t find a happy accuracy/velocity load at magazine length then I’ll revisit the magazine limitation. Barrel will be ready to go this week but I don’t have dies so can only fireform brass.

 

[bart brennan]

I'll be curious how this turns out for you as I'm building one myself off a tikka t3. I got in on a manners group buy for an eh1 tikka mini chassis and it only came in short action. Heard ADG brass will be making short shouldered brass you can fireform like an Ackley. I have a bunch of H4831sc but am also curious about rl23. Will be trying berger 175eols.

 

[CA48]

I have a 6.5SS in a light hunting rifle. It's very accurate and easy to load for. Norma Brass has been good and lasts awhile but adg is coming out with brass soon. I send my brass to Rich and for a dollar a case it comes back necked turned sized to 6.5 and has a false shoulder so it's ready to fire form. I can seat bullets way out there and it still fits in the mag. The 7 SS should be a great round for 1000 yard BR.

 

[KMG]

I was one of the first ones to jump on Rich's band wagon 2014 when he & Bigngreen were putting the first info out there about the cartridge on the web. I saw the genious in the design of this improved case called the Sherman Short Mag. I've had my 6.5SS for three years now & love it. It is inherently accurate & super easy to reload for. Every bullet/powder combo that I have run thru this rifle has shot sub MOA at worst. Mine is on a Savage 11action, 32" Bartilein 8t with brake, & AICS mags. Mag length for the WSM mags is 3.010" for mine, no binder plate at the back. I'm sure you will be more that pleased with the results of your decision to go with a 7SS. Rich is a great guy to deal with & a wealth of information. Good luck with your build. Kevin

 

[bigngreen]

I've built a number of 7 SS's including Rich's and I've built an equal number of 7 SAUM's, the SAUM will not run with the SS in a true short action platform, even in a longer action the SS holds pressure better and is more efficient so it runs faster even using the same brass. Accuracy is easy, I've not seen one that was difficult to tune! The ADG brass is moving along, I can't share where Rich is at in the process but the ball is rolling right along!! In a short action it's the sauce!!