This is the first time out with the chronograph, and I was admittedly impressed with the ease of setup: put a battery in, put the skyscreen stalks in the slots, turn it on, and shoot through the "V", remembering to aim high to compensate for mechanical offset due to the optics being a few inches above the bore because a low shot that "looks right" through the scope has taken out countless chronographs over the years. Then just read the bullet velocity. Easy, peasy.
I fired five shots for this first test, as I'm working up a new .44 load with a 300gr. Hornady XTP over Titegroup. Today's test load was 8.5gr. of Titegroup, each round hand-measured.
On the plus side, I only had a deviation of 7 feet per second between the fastest and the slowest round in the group, with the slowest being 1053fps and the fastest two both clocking in at 1060fps. So consistency is definitely there.
ON the downside, I was going for subsonic loads, with the maximum velocity sought being 1050fps, and these were just a touch too fast, each one giving off a minor sonic crack that was still comfortable to shoot without ears, but also still audible enough to get the guy on the adjacent rifle range to ask me if I was shooting .22 shorts. I can do better. Next test loads will be half a grain less, and we'll see what we get from those.
The rifle: A Ruger 96/44 lever-action with an integral suppressor done by SRT Arms.
You have the neatest toys!
ReplyDeleteThat would get you soooo busted here in Kommiefornia....
ReplyDeleteAnd that's why I don't live there.
DeleteYou got the USB thingy and software to download your chrono data to the computer so you can you know, do geeky graphs and stuff =) I do. I love that little thing!
ReplyDeleteVery nice! And technically, anything below 1160 is sub sonic. :-)
ReplyDeleteThe rounds fired today had a pretty audible argument to the contrary. But two test rounds stepped back half a grain tonight were pellet rifle quiet.
DeleteThe speed of sound will vary depending on atmospheric pressure, temperature, and humidity.
DeleteYes you can use the chronograph for measuring bullet velocity just like you are supposed to. But half the fun is using something in a way the manufacturer never intended. Is it possible to use the device to measure really high speeds like the speed of a german shepard when heading for the food bowl. Or when the dog is heading for the door to protect you from the mailman or the delivery guy.
ReplyDeleteOr to measure the average airspeed of a laden swallow.
And does your suppressor have the Hollywood switch so that a mach 3 bullet can leave the muzzle and be perfectly silent?
And I am looking forward to the results of 45 ACP fired from a Reising Submachine gun.
John in Philly
Do you have to account for density altitude?
ReplyDeleteYep. Altitude and temperature both factor in. My goal is a round that stays subsonic even in cold weather and at higher elevations. The rifle should sound like a pellet gun as it throws a 300gr. bullet right around thousand feet per second.
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