7mm STW ballistics

[GeorgiaBoy]

I have been looking at the ballistic charts I can find and I have noticed that they all seem to be ending for the 7mm STW around 500 yards. My .30-06 is capable of reaching out to 1000 yards so I know that a magnum round will do that and then some but I can't seem to find much on the ballistics sites about it and as I don't trust Wikipedia for something like this I was wondering if someone would be so kind as to share the ballistic properties of the 7mm STW such as range and trajectory etc. any info would be appreciated

 

[Defens]

The best thing to to is to either use an online tool, or download one of the many free or commercially available ballistics programs and build your own chart. Most of the good tools already have the BC and other data needed for the major bullet makers already included, so all you have to do is pick a bullet, enter your muzzle velocity, and you're good to go. The better tools allow you to add atmospheric data (density altitude, elevation, humidity, temperature) and other data to refine the calculations. Then you can select what range you want your bullet drop chart to cover and how fine the increments should be (10 yards, 25, 50, 100, etc.)

Check our Modern Ballistics by Joe Huffman, or the tools by Sierra Bullets, or others - you'll fnd them to be very handy.

 

[MudRunner2005]

Here's a few screenshots of my STW ballistics table using a 180 Hybrid at just under 3K fps MV.

 

[7STWVA]

Sometimes we treat these ballistic charts like lunar tables or forecasts for a total eclipse of the sun for the year 2058.

Has anyone on this forum fired any of their loads over a 2 chronograph set up and then reported the data? Just curious...other wise we are in the realm of the MPG "estimates" we see on new car window stickers.

I remember a conversation I had with Randy Brooks one year at SCI, right after Rick Jameson published his early 2 chrono results in Shooting Times:

"Randy, why is it Rick calculates all of the Barnes BCs at least .200 below your published figures?"

"Well, Pardner, we just have to stay competitive "

 

[WildRose]

Sometimes we treat these ballistic charts like lunar tables or forecasts for a total eclipse of the sun for the year 2058.

Has anyone on this forum fired any of their loads over a 2 chronograph set up and then reported the data? Just curious...other wise we are in the realm of the MPG "estimates" we see on new car window stickers.

I remember a conversation I had with Randy Brooks one year at SCI, right after Rick Jameson published his early 2 chrono results in Shooting Times:

"Randy, why is it Rick calculates all of the Barnes BCs at least .200 below your published figures?"

"Well, Pardner, we just have to stay competitive "

How many people do you know that own 2 chronographs?

You'll find that most of us here verify our drops at several ranges and then use the proven BC and velocity data to build or drop cards or program our data with.

 

[jw308]

How many people do you know that own 2 chronographs?

You'll find that most of us here verify our drops at several ranges and then use the proven BC and velocity data to build or drop cards or program our data with.

Amen...

 

[Lefty7mmstw]

How many people do you know that own 2 chronographs?

You'll find that most of us here verify our drops at several ranges and then use the proven BC and velocity data to build or drop cards or program our data with.

I've got a ced and a oehler 35p available to me (I own one and am 1/2 owner of the other).... most of the better chrono's; are pretty darn accurate... the $100 wonder chrono's aren't worth their weight in manure, and the mid line chrono's sometimes are picky about when they want to play nice (like my ced) but I've seen 3500 fps with a 140 in a 25" bbl.d stw and 3000-3100 fps with a 175 grain pill over the oehler. I've got to get my hands on the oehler again to play with my 7rum a bit with heavy's.

 

[ncwg2boatguy]

I use JBM ballistics. If you enter your info as accuratley as possible it's pretty **** close.

 

[J E Custom]

I have been looking at the ballistic charts I can find and I have noticed that they all seem to be ending for the 7mm STW around 500 yards. My .30-06 is capable of reaching out to 1000 yards so I know that a magnum round will do that and then some but I can't seem to find much on the ballistics sites about it and as I don't trust Wikipedia for something like this I was wondering if someone would be so kind as to share the ballistic properties of the 7mm STW such as range and trajectory etc. any info would be appreciated

My first long range (1,000 yard) match rifle was a 7mm Rem mag and shooting 168grain SMKs
it was a beast (3254 ft sec)and was laser flat using a 31" barrel.

The first time I saw an article about the 7mm STW, I knew I had to have one. No one made ammo
or brass for it and you had to use 8mm rem brass to load it. the 7 STW has close to 25% more energy than the 7 mm Rem Mag. The 7mag was touted to produce 3000 ft/sec with a 150 grain bullet. The 140 was 3100+ ft/sec in a standard length barrel.

Just for drill, I had my 7 STW barreled with the same 31" barrel for a good comparison. I exceeded
most bullets limits with it and saw accuracy go away when it reached 3800 ft/sec with the 140 grain bullets. So with 3700 ft/sec velocity (600 ft/sec more usable velocity than the 7 mag and well beyond any ballistic tables and load data everything had to be chronographed and drop charts were necessary to effectively hunt with the STW. it's effective range is well past 1000 yards and with close to 500 ft/sec more than a 30/06 with the same bullet weight it is a much better performer than the 30/06 (Even though it is a great cartridge).

With todays lawyer involvement in loading manuals it is hard to fine loading data that shows the true potential of the 7 STW so I recommend that you try to find an old Hornady or Speer loading manual to see some real world loads and trajectory's (This would also be a good way to compare the two cartridges). When A Square started loading ammo for the STW there advertised loads using a 140 grain bullet had a velocity of 3550 ft/sec in a 26" barrel, top loads are now listed at around 3400 ft/sec.

The 7 RUM can be loaded to 12% more energy than the STW (But that's another story).

PS: all of my load data velocity's were chronographed over a Ohler 35 p and later verified using a newer version in combination with the Magneto Speed. So my loads have been chronographed over 3 different chronographs.

This site has a section dedicated to the 7 STW and there is a lot of information on this cartridge.

J E CUSTOM

 

[ncwg2boatguy]

How do you like the magneto speed barrel mount chrono? I want to pull the trigger but the reviews I have seen seem to be from suspect folks who sell them and not the actual end users (Shooters) Seems almost too good to be true. I would value your opinion as I do most on this great site. living in VA its hard to find places to actually use my 7 STW to its full potential. But at 850yds nothing I have owned or shot compares when hand loaded. Im running 72.8gr of RL22 and a 162gr Amax. Its right a laser.

 

[J E Custom]

How do you like the magneto speed barrel mount chrono? I want to pull the trigger but the reviews I have seen seem to be from suspect folks who sell them and not the actual end users (Shooters) Seems almost too good to be true. I would value your opinion as I do most on this great site. living in VA its hard to find places to actually use my 7 STW to its full potential. But at 850yds nothing I have owned or shot compares when hand loaded. Im running 72.8gr of RL25 and a 162gr Amax. Its right a laser.

I got your PM and replied to it, In short I really like it and use a lot.

J E CUSTOM

 

[ncwg2boatguy]

Jerry,
Thanks for the reply and info. Guess I am going to pull the trigger and get one. I have 377 acres so no issue with others at the range .

 

[muliehunter]

has anyone else used the labradar

 

[Lefty7mmstw]

nope on the labradar...