IMR 7977 Enduron

[jjmp]

Laynes powder charge was 78 gns of IMR 7977 for the Swift 160 a-frame bullet,and for the Sierra 175 gn gamekings the charge was 75 gns of same IMR 7977 powder. 3 different temp ranges were used with each of the 2bullets stated above, Swift 160A-F Tested at -15 degrees tmv was 2933 fps sd was72, 100 yd group was1.29. 2 temp same 160 saf was +78 degrees tmv was 3006 fps sd was52,100 yd group was1.34, 3rd temp same 160 saf, was +140 degrees tmv was 3019 fps sd was 25 ,100 yd group was 1.20,( note ) col was 3.600 ,jump to lands was 0.15 thou.case was FC federal, primer was federal 215 mag primer, with 160 SAF bullet. rifle Ruger #1with a 26 inch bbl. test for Sierras 175 gamkings were as follows col was 3.620 =0.40 thou off lands same FCbrass same f215 primer ,-15 degrees tmv was 2783 fps,sd was 67, 1oo yd group was 1.37. 2temp was +78 degrees tmv was 2852 fps, sd was,29, 100 yd group was 1.18. 3rd temp was+140 degrees tmv was 2857 fps,sd was33,100yd group was 1.24. all this info is for the 7mm-STW Only.!!! thks Layne! my above post explains where an when LS wrote the article ,Long live the 7STW!!!

 

[LONG RANGE 7MAG]

I just went to the alliant website and they have some data for R26 and 7 STW.

For a staring point, you can cross reference loads.

Then break out the chronograph and start testing.

Again, please advise us of your progress and results.

 

[LONG RANGE 7MAG]

I shot my STW this past weekend and learned a few things. I bought a GAP rifle off of this sight that is throated for the 195s. The load was 72.5 grains of RL 25. I shot the ammo that came with the rifle and also loaded my own at the same specs. It shot 3/8 or better @ 100 yrds, @ 2850. I had to try the Mcwhorter load that I read about on this sight that was using RL 26 since I have a case of it. 75 grains. It shot @ 3050 through the same hole. Just my experience with the 26 and I am very impressed to say the least! I have read on here about RL25 being the solves all and it might be for you, but if you get a chance try the 26. By the way, no pressure signs at all. I am in WA state and am @ 2400 elevation @the range. I am going to go out as soon as snow melts and shoot it @ 6000 elevation. Will let you know how it goes. Thanks for all the info!

 

[LONG RANGE 7MAG]

Got to stretch out the old STW on Sun. 1225 yards! It is a hammer! Mcwhorter load/ 75 Grains RL26 Berger 195s, 3050 fps. Verified through my G7 rangefinder .No pressure! Im done! Waiting on my next hunt!