FYI this is 142 smk bullets with 42.5 gr of H4350 in a Lapua case. My strelok shows about 50 fps faster according to the drop vs where I was without the can.
I've decided my F1 Shooting Chrony isn't cutting it anymore.
I've had sporadic readings lately and today it really didn't help my confidence in this chrony one bit
Tested my 260, suppressed vs non suppressed to see poi shifts and velocity changes. Shot out of a dirty barrel (at least 50 rounds since last cleaning. This chrony had me at 2835 fps for speed last Summer when I developed the load. Today my results were:
First shot suppressed: 2744
Second shot- non suppressed: 2740
Next 3 shots were suppressed, removing and reinstalling the suppressor between shots.
1) 2998 fps
2) 3014 fps
3) 3020 fps
So either non are correct, or this suppressor slows the bullet almost 100 fps the first shot them speeds them up almost 200 fps for the consecutive shots. All shots suppressed were bout .5" at 100 yards.
I noticed some stiffer bolt lifts due to the back pressure of the suppressor, which is why I wanted to test the velocity difference today. I had no stiff bolt lift on any suppressed shots, including the ones that apparently are traveling at speeds that are unheard of for this cartridge.
So what's a good chrony to use. I'd prefer one that isn't terribly fancy as I just need to readout to be accurate.
Or is this chrony correct and I just have the greatest suppressor on earth? Lol
FYI this is 142 smk bullets with 42.5 gr of H4350 in a Lapua case. My strelok shows about 50 fps faster according to the drop vs where I was without the can.
For years the Ohler 35 was considered to be the best of the best chronagraphs.
A few years ago on the LRH site an extensive comparison between it and the Magneto Speed
took place. The consensus was that both units were of equal ability as for performance.
Fact is one of the people involved in the test sold his Ohler after the test.
Buy a Caldwell for seventy bucks, mount it on a garage-sale photo tripod, and hook it to your smart phone. Best bang for the buck, newly designed electronics, fast clock speed, etc.
Mine works great.
Check out this link, which BTW: is on page two of this board.
http://www.savageshooters.com/showth...e-did-I-see-it
Thanks Texas, didn't do much research prior to posting. I did receive several pm's about the magnetospeed and that is what I will go with. Will Proly get the v3 as I do need it to attach to my suppressor
I'll be getting one soon too..may have to sell my first born to afford it....Ha-ha
Magnetospeed V3 is my only suggestion. It's to easy to set up and stays very consistent.
Sierra is better than many for giving accurate BC's, but if you are using the G1 number, don't ever expect it to be exactly correct in terms of drop. Supersonic flight with that SMK isn't very well "described", use the G7 number, until you approach trans-sonic. Once you go sub-sonic then the G1 fits beautifully.
Also I would offer a few things on the Chrono. Don't think of any one of them as an absolute, rather an idea. You should have a much larger sample size for an average, and since you are loading extruded powder by weight instead of volume, you will have more variance in BR, and thus velocity than you may expect.
With the magnetospeed, if you shoot it a lot, then plan ahead and buy a few of the rubber pieces that "watch" the bullet fly over it. They are a wear item and the powder will erode them away with time.
I'm a firm believer in the theory that if it bleeds, I can kill it.
I can provide this information... My Caldwell reads about 40 to 45 FPS faster than the Magnetospeed.
If you want to get real froggy with accurate chrono data you could always order up the new LabRadar. It can calculate velocity out to most distances you'd be willing to shoot. Doesn't attach to the rifle. Don't have to shoot over top of it. Basically your own personal radar, that you use to track your bullets. Just as accurate as the MagnetoSpeed and once programed it might even be faster to set up.
+1 on labradar. Had mine about a year. Once set up properly, works awesome. Worth the bucks.
Savage 10 FCP-SR 308, 300BO PCS
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