7mm stw with 195 berger eol

[jshepherd61]

Hi all,

I have built a new 7mm STW. The build is as follows:

28" lijja medium weight barrel.
1:8 twist.
Custom brake - by my smith.
Accurized Rem 700 action.
MDT ESS chassis
Trigger tec trigger.
Custom chamber to shoot Berger 195 grain EOL bullets.

Brass - Hornady.
215 primers.

I am planning to start developing loads using retumbo, IMR 7977, and IMR 7828.

I need specific start load data for one or all of powders. I know that I will start below any suggestions given. I have contacted IMR, Hodgon, and berger. No load data has been provided.

Any help would be appreciated.

This is what Berger gave me to start fo the same Winchester m70 LRH 28" Bartlien barrel. They gave me this info for the 195 EOL but I could not get the velocity and accuracy I wanted.
Retumbo 78.2 gr
Primer: FED GM215M
COAL THEY GAVE: 3.795
My COAL: 3.895

Went back to 168gr Nosler ABLR

 

[jshepherd61]

I'm pretty ignorant about some of this stuff. What is the "STW"?

7mm Shooting Times Westerner developed by Wayne Simpson and named after the magazine he wrote in. Excellent cartridge was going away but starting to come back Winchester announced they will start chambering in it again next year.

 

[HobieH3]

I'm pretty ignorant about some of this stuff. What is the "STW"?

Shooting Times Westerner
1st rifle built by Kenny Jarret in 1987.

 

[Satterlee Scott]

I've had the opposite experience with 7828. I've found it to be very stable in over 40º temp swings. I've had temp sensitivity with H1000, and most claim it's not sensitive.

I did a test from the freezer and 115 degree water 148 fps spread on multiple occasions. I tested 6.5 SAUM, 7 SAUM, 270 win, 300 WM and 300 Norma the bigger cases showed more ES then the smaller cases. Almost 200 FPS in the Norma. The IMR enduron powders are pretty stable I use .4 fps/degree with them.

 

[Satterlee Scott]

This is what Berger gave me to start fo the same Winchester m70 LRH 28" Bartlien barrel. They gave me this info for the 195 EOL but I could not get the velocity and accuracy I wanted.
Retumbo 78.2 gr
Primer: FED GM215M
COAL THEY GAVE: 3.795
My COAL: 3.895

Went back to 168gr Nosler ABLR

Retumbo would be a great powder for the heavy pills

 

[MudRunner2005]

I did a test from the freezer and 115 degree water 148 fps spread on multiple occasions. I tested 6.5 SAUM, 7 SAUM, 270 win, 300 WM and 300 Norma the bigger cases showed more ES then the smaller cases. Almost 200 FPS in the Norma. The IMR enduron powders are pretty stable I use .4 fps/degree with them.

Would be interested to see the results of this test on the ew Enduron 7977 and 8133.

 

[jshepherd61]

Retumbo would be a great powder for the heavy pills

It's great for the STW! I've tried the Enduron's, 7828, 7828 ss, BMG, RL19, RL25, H1000, US869 and Ramshot Magnun and Retumbo in my loads has the best cosistancy, ES, velocity and accuracy pushing a 168 gr ABLR at 3,352 fps with a .214 group. It's a barrel burner! Been through three Bartleins! I load at 5623 alt and hunt around 10,050 in Gunnison area Mt. Teocali. The Enduron's couldn't come close to the stability! Been loading the STW since 1998. All of the powders listed I have loads for if you want to contact me and I keep all data. The velocities are direct muzzle using a magneto speed.

 

[jasonco]

H1000 was the most consistent of the powders, back in the day, when it wasn't many options. Then Retumbo came out and it was the go to powder for 175 grain + bullets, I have it by the keg! H1000 was used for the 140-160 grain class bullets. In my rifle, I can seat bullets long!

L-R 7STW 180 VLDH 83/H5010, 7RUM 150 Scirocco 93/H1000, 28 Nosler 180 ELDM 78.4/Retumbo

 

[jweigel]

My STW refresh is built very similar to yours. If you can find some N570, it is a great powder getting about the most velocity and pretty clean burning.

Here are my results.... https://www.longrangehunting.com/threads/7stw-refresh.191205/#post-1343198

jjw
ND

 

[jshepherd61]

My STW refresh is built very similar to yours. If you can find some N570, it is a great powder getting about the most velocity and pretty clean burning.

Here are my results.... https://www.longrangehunting.com/threads/7stw-refresh.191205/#post-1343198

jjw
ND

What are you getting for velocity? I'm looking to stay above 3,100

 

[jweigel]

You can 3100 and more....but I found 3084 to be most accurate and not to hard on the soft Nosler brass I use.

jjw
ND

 

[vancewalker007]

My father, uncle and I built 3 STWs back in the 90s when Lanye Simpson first published info on it. We had to fire form cases using 300 Weatherby case. We used the max load of the 7mm Weatherby as a starting load then increased powder SLOWLY until we had heavy bolt lifts and usually backed down the heavy bolt lift charge by .2 or .3 grains and recorded the result as the max for the given bullet and powder combo. I was shooting mine (second barrel) up to a couple of years ago. Its been converted into a different cal now.

 

[curtiscd]

This is the data I collected with a Magneto on my 26" barreled STW. HBN coated bullets. 8mm Remington brass. I don't have my book w/ me for charge weights, but I do know that I settled @ 80.6 grains N570 @ 3086 fps. The velocities listed are all in .5 gr increments. I worked up to mild bolt lift and ejector marks with each powder. I have shot this load out to 2119 yards with excellent success.

 

[ronstone09]

I ve had a 7mm STW for a long time and have used 175s in it to drop moose in canada and its a tack driver !