6.5- 284 and chronograph

H

holl

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I'm working on a load for a 6.5x284 26" douglas barrel. Using SMK 142s and H4350. I'm shooting these over an Oehler 35 chrono. I'm getting good velocity and some pressure signs in the 43g range. The barrel shows to shoot faster than the Sierra manual shows it ought to with that load. Is that unusual? I've always noticed the manual showing a faster velocity than what the Chrono showed. Do the chronos ever have to be calibrated? Just curious...
My next step is to back down on the powder and start adjusting the seating depth. comments?
 
I am not familiar with the Oehler hands-on but I own a Pact chrono. The skyscreens have got to be spaced exactly(36" in my case) apart as to what the chronograph is calibrated and parallel to one another. It also depends upon how far they are from the muzzle. This may be too basic for you and I appologize if it is, I'm new to this site and am not familiar with everyones experiece.
 
No, it's not unusual because you are not using the same barrel that the folks at Sierra used. How much faster is it shooting?
 
I think the chrono is set up correctly. I will have an error message if the screens are not exactly correct. The gun is 150-200 fps faster than the manual.
 
Hey holl ! Do not have the manual, so don't know what fps you are referring to? 43.0 gr. of H4350 is a soft load for 6.5x284, so don't know why you are having stickie bolt & pressure. Most loads of H4350 for 139 to 142 bullet run 48.0 to 49.5 grains with no problems and FPS from 2950 to 3000. I would guess with 43.0 gr. and your short barrel the fps at muzzle is close to 2500 (+ or - 50).
Give us some more feedback on what componets you are using ie;
Brass-Primer-Bullet(s)-Seating depth etc. and we will see what we can come up with.

Gary.
 
hornady brass, CCI br primers, H4350, 142SMK loaded touching the lands. Chronographed at 3000-3100fps. No neck turning. Don't know what chamber.
I guess I shouldn't worry that it takes less powder than the manual states to get velocity.
 
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