7mm STW vs 7mm WBY

[MudRunner2005]

The SAAMI pressure ratings are 65,000 psi for both the 7mm Wby and 7mm STW and The 7mm RUM

The 7 Rem Mag is 61,000 psi for good reason.

What reason would that be?

 

[Lefty7mmstw]

The SAAMI pressure ratings are 65,000 psi for both the 7mm Wby and 7mm STW and The 7mm RUM

The 7 Rem Mag is 61,000 psi for good reason.

I am trying to ascertain where I got the 64,000 psi # from the 7stw from... I'm sure I saw it in print otherwise I'd have checked saami. Likely some loading article sorting the stw with the 300win and 338win, which are at 64,000psi. The roy, rum, and stw are all at 65,000 psi with a max sample of 69,100 psi.

http://www.saami.org/specifications_and_information/specifications/Velocity_Pressure_CfR.pdf


it is interesting that the 25 roy and 270 roy are at 62,500 psi.... probably for good reason too......

 

[Deleted member 46119]

it is interesting that the 25 roy and 270 roy are at 62,500 psi.... probably for good reason too......

Oops engineering.

 

[BPollard]

Thanks for the info everyone. I am not ready to buy anything nor leaning one way or the other right now. It is good to see that there is a real world difference between them.

I had just sort of looked at them all as "another":
- 375 H&H daughter round
- Blown out
- necked down or necked up to xxx mm
- with the newest hi-zoot shoulder angle of the day
- and a new name stamped on it to sell new guns
- another cartridge for the ammo makers to build for, when they can't keep up with even basic stuff

I don't mean to criticize or anything, its just that there are a heck of a lot of minor cartridge variations between 6 and 7mm, and I am a pretty simple guy. A person can spend a month just to start to understand all of the variations in that group.

It does sound like a hard hitting round - probably need to fire one a few times.

What kind of distance do you plan on Shooting? I have a seven Weatherby mag and I shoot 150 barns out of it. 3130 ft./s dropped an elk at 603 yards couple years ago. the next day my buddy used my gun and shot an elk 75 yards. Dropped it in its tracks don't need to shoot heavies all the time. I was trying to get her to shoot the heavy bullets she's a little finicky because of the barrel twist I got it able to stabilize 168 bergers but it doesn't like the 185 so I'm content leaving it at that
I am looking on your thread right now to see if there's something newer and may be better in a 7 mm caliber to shoot the higher BC heavy bullets.

 

[HarryN]

What kind of distance do you plan on Shooting? I have a seven Weatherby mag and I shoot 150 barns out of it. 3130 ft./s dropped an elk at 603 yards couple years ago. the next day my buddy used my gun and shot an elk 75 yards. Dropped it in its tracks don't need to shoot heavies all the time. I was trying to get her to shoot the heavy bullets she's a little finicky because of the barrel twist I got it able to stabilize 168 bergers but it doesn't like the 185 so I'm content leaving it at that
I am looking on your thread right now to see if there's something newer and may be better in a 7 mm caliber to shoot the higher BC heavy bullets.

Thank you for looking at my older posts. I have been away for a while and am sort of coming back to get started again.

Life has been slightly complicated, so right now I am just going to look at adding a simple scope to my .270 win. - hopefully this fall sometime.

For now I am just going to read / search the classifieds for a while.

Take care, Harry