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Barrel Mounted Chronograph

Posted: Wed Apr 11, 2012 1:01 pm
by Vartarg
I thought this might be of interest....and I"m not selling anything....I'm just a customer.

Setting up and dealing with a skyscreen chronograph is a PITA based on my experience....and yet what a huge difference they make in load development and evaluation.

When I ran across this product, I bit the bullet and ordered one, then took it to the range with my CED2. Here's a link to my post over at 6mmBR.....

http://forum.accurateshooter.com/index. ... sg36060801

They're here: http://www.magnetospeed.com/

You can also find an extensive review over at:

http://www.snipershide.com/forum/ubbthr ... t=2&page=1

George

Re: Barrel Mounted Chronograph

Posted: Wed Apr 11, 2012 2:27 pm
by RAMOS
Now that is cool!

Re: Barrel Mounted Chronograph

Posted: Mon Apr 16, 2012 12:27 pm
by Fred_C_Dobbs
I've come across several reviews on that chrono recently -- from shooters, not magazine writers -- and most were pretty favorable. It's super-fast/easy to set up. And because it doesn't rely on light, it misses out on most of the problems "conventional" chronos have. But mounting it requires some D-I-Y if you have a muzzle brake or suppressor. And because it's a weight on the end of the barrel, it is going to affect your POI. I almost always shoot over a chrono when I'm at the range because that's one of my reloading QC measures, lets me monitor how my SDs are running. Because of that, I'd have to re-zero after a range session using the "bayonet" chrono before I could shoot it in the field. Or I could just go hunting with the chono still strapped to the barrel.

Re: Barrel Mounted Chronograph

Posted: Mon Apr 16, 2012 3:32 pm
by Vartarg
Fred: I don't believe it will affect the POI. As part of the "dialog" over at 6mmbr, I did a little accuracy comparison. Here's the post. NOTE: I'd been shooting at 200 yards, and hadn't adjusted my scope when I used 100 yards for these strings. After the first three series I adjusted the scope to bring the groups down 2 inches.....just FWIW. I don't believe this is the end all and be all for chronographs, but it sure is a step in the right direction. George

Here's my follow up report on accuracy with the Magnetospeed chronograph:

i loaded 30 6BR rounds with 30.6gr of CFE223, and fired 15 rds with the Magnetospeed bayo device on the barrel, and 15 rds without it. In between, I cleaned the barrel and allowed it to cool off, and then fired a fouler. These rounds were fired at 100 yards.

Here are photos of the targets, and most of the information is self explanatory. I have no (good, i.e. exculpatory :-[) explanation for group #2 on the first target....wish I did.

You will all draw your own conclusions based on what you see, but I don't see any evidence that having the chrono gizmo hanging on the end of the barrel made any difference in the accuracy.

(In responding to a question on the Saubier forum, the small caliber folks, the question was raised about whether it would "see" .17 caliber bullets, since some folks had trouble with their skyscreen chonographs with them, especially if lighting was not the best. I fired 10 rounds of .17 Fireball 25gr Vmaxs with the Magnetospeed, and they all registered normally.)

Comments and questions are welcome. George

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Re: Barrel Mounted Chronograph

Posted: Sun Apr 29, 2012 10:03 am
by Wrangler John
Neat little gadget. My two Oehler chronographs are such a chore to set up, I'll have to try one when they have caught up with demand.

Here's a prediction I made a few years ago about the pending electronic revolution in shooting.

The digital rifle scope will become an automated information center. No longer a pure optical device, the scope will display sight picture and information on a digital screen. It will be capable of a heads-up display on purpose built shooting glasses or a device mounted display. The display will function in normal daylight, or in a passive FLIR mode for near zero lux capabilities. It will have image correction capabilities for contrast, brightness and color. Both still photo and video capture will be standard.

The scope will measure humidity, temperature and air pressure, the latter interpreted to altitude.

We already have scopes with laser range finding capabilities, but these are primitive compared to what is possible.

Chronograph data will be collected by the scope directly by either thermal or laser imaging, or both, imaging of the bullet flight to a predetermined range. Velocity will be represented as either the traditional muzzle velocity or a scale of deceleration to the target. Velocities will be known at every point along the bullet's path. Ballistic drop, spin drift and wind deflection will be displayed as a track on the screen or a representation of a X-Y-Z 3D graph. These factors could be saved but not displayed for downloading to a computer. It will no longer be necessary to calculate a range card for each bullet and load, a few shots and the scope will accurately calculate the data and save it as a selectable choice.

The scope will also measure cant, displaying a signal when the rifle has been leveled, or making the correction automatically without shooter interaction.

Ambient wind direction and speed will be measured by laser or microwave (radar) measurement of dust mote movement and displayed on the screen. Capabilities will include measurement of wind at several ranges over the course and be computed to the actual effect on the bullet. All this data will be combined with the known velocity track of the load being used, and the range to target, to automatically correct the reticle position prior to the shot. Reticles cluttered with dots and lines will be unnecessary, there will a simple color change to the reticle signalling the correction has been made.

Factory ammunition will include a QR code that will program the scope for a given load. This will allow first shot accuracy after initial sight in.

The possibilities are endless.

Re: Barrel Mounted Chronograph

Posted: Tue May 01, 2012 6:59 pm
by Fred_C_Dobbs
A member at the sniper's hide tested his .308 with and without his magnetospeed and found it changed POI @100 yards by about 3 1/2 inches.

Re: Barrel Mounted Chronograph

Posted: Wed May 02, 2012 10:42 am
by Vartarg
After reading Fred's post, I decided to take a look just at POI in relation to having the Magnetospeed on or off the barrel.

I was going anyway to do some other work, so I set up an extra target @ 100 yards and fired 15 rounds. The rifle is my Savage 6BR, with 105gr Berger VLDs, Lapua brass, BR4 primers and 29.5gr of H4895.

The first five rounds, on the left, were with the chronograph mounted on the barrel....I took the chrono off for the middle target, and put it back on for target number 3.

My appraisal is that although accuracy was not compromised, there was was definitely a shift in POI...slightly over 1". That 11 o'clock flyer on target one is on me. :oops:

Not having read the report on Sniperhide, I'll still say that I have a hard time believing that you'd have a 3 1/2" shift @ 100 yards......JMHO. I'll definitely test some more, with other calibers.

Thanks, Fred, for your posting.....

George

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Re: Barrel Mounted Chronograph

Posted: Wed May 02, 2012 1:55 pm
by Sth Oz Dan
Doesn't take much to shift POI
I had a scope mounted LED spotlight. When I took it off I was shooting 1&1/2" high and 1" left - that's 1.8" out.

Neat gadget though (chronograph), and if your shooting on target without it mounted, then that little shift wouldn't hurt while you're testing some loads.

Re: Barrel Mounted Chronograph

Posted: Wed May 02, 2012 2:34 pm
by Vartarg
Sth Oz Dan wrote:
.......and if your shooting on target without it mounted, then that little shift wouldn't hurt while you're testing some loads.
That's my conclusion as well......

George