RE: Slowest STW known to man
 

Let us know how it works because I’m very curious about the distance on that Chrono. I always set my chrono at 10 feet and sometimes wouldn’t get any reading...

RE: Slowest STW known to man
 

I use one quite often and usually set it up 10-12 feet away. I don't even know it is there now.

This is from their manual:




4. To safeguard the instrument (and to obtain the best results), the projectile must pass between 6 and 4 inches (15 and 10 cm) directly OVER the Twin Lenses in the black plastic boxes at the front and back of the chronograph. These are the chronograph’s "eyes". Attaching pieces of dark-coloured tape on the guide rods (wire rods) at these heights, will help you to accurately aim your shots.


5. The Shooting Area. Every Shooting Chrony and Master Chrony comes equipped with an adjustable-size, triangular shooting area (actually an upside down trapezium) from 8"X8" to 14.5"X14.5" (Fig. 2). All Chronys come equipped with four 9.25" wire rods as well as four 6.5" wire rods with brass connectors attached. The 9.25" wire rods are to be inserted at an angle into the outer holes visible on the black plastic boxes of the unit. On bright, sunny (blue sky) days, install the white plastic diffusers on top of the wire rods (to simulate clouds). The photo-sensors are pointed at the diffusers, which create a white background (clouds or diffusers). On cloudy days, use wire rods for alignment, but without the diffusers.


6. Chronographs should be at least 10 feet (3 m) from the muzzle of a high-powered rifle, but can be closer to guns with a lesser blast. Five feet (1.5 m) is about right for .22 rimfire firearms. Shotguns should be fired at 5 feet because of the spreading pattern of the shot and errant wads. Arrows must be clear of the bowstring before passing over the first "eye".

Hope this helps

RE: Slowest STW known to man
 

I had the same problem with mine. You need to carefully bump up the powder on the STW. The maufactures are waaaaaay too conservative. I own a Sako 75 and was getting anemic velocities with mine. A fellow on another forum had the same problem until he bumped it up a full grain and 1/2.......then 3300+ was achieved instantly. I did the same with mine, and there are no pressure signs at all....none nada. I had to quit before deer season, however, when the weather gets better, I'll be doing some futher testing.....the bottom line is this.....7mm STW published loads are so conservative it isn't even funny.....it's pathetic! I have narrowed my powders to RL22 and IMR 4831.....this story is far from over. The factory Federal premium 150 grainers chronied at 3280 in my sako......wonder what they are using? Not Hodgdon data that's for sure!!! PM me for other findings. Regards, Rick.

RE: Slowest STW known to man
 

Big Country- I got it out of the Nosler book. It's H870, 79.5 grains, at 3112 fps. Little slower then I remembered, but still pretty quick for a rem mag.

RE: Slowest STW known to man
 

Yea, my load is supposed be kicking out at 3100fps too, but its more like 2900fps. Hope that load works out for you.

RE: Slowest STW known to man
 

You Need to go Over to Longrangehunting .com and ask Kirby Allen or Fifty Driver he has built a Ton of STW's .
Sounds like the wrong bullet for the Twist of the Barrel. He specializes in that kind of Calibers , He makes a smoking 257 STW at 3900 fps.

RE: Slowest STW known to man
 

I appreciate the advise but its shooting very accurate. I don't see how velocity has something to do with twist.

RE: Slowest STW known to man
 

I have loaded up to max "book" load but never saw any pressure signs, but accuracy started falling down. I was reading old layne Simpsons loads and dad gone, that guy really pushed those loads. His max load for 160gr bullet was 86gr of H1000. And that was kicking it almost 3400fps. I don't know how he didn't see any pressure signs.

So tonight I loaded up several different combos to try. One was with RL25 78gr to 80gr, and another was H1000 78gr to 80gr. I was getting 3050fps with 78gr of H1000 last year and got average 1MOA accuracy but didn't go past 78gr. Well see how accuracy goes with 80gr.

RE: Slowest STW known to man
 

Those are nice loads. I wanted to try some of that WC872. Not sure what I would do with 8lbs of the stuff. I wonder if its like AA8700?

RE: Slowest STW known to man
 

Ridge I see you shoot one of Kirby's 7 MM 's . He builds some super Rifles and Calibers. Kirby is working some New Allen Magnums.