Magnetospeed Sporter ~ $189

Pros?  Cons?

LF

Not sure about that model.  I have a V2 that I love.  I dont have to worry about lugging around a tripod or shooting my chrono.  The downside is that I tend to get a POI shift of about 1 moa when using it.  Also, with the V2, I like the fact I can just remove the SD card and plug it in my laptop and output a CSV file.

Good stuff.

I've read about poorer groups when shooting with the "bayonet" attached.  But, frankly, I would expect something hanging off the barrel to change a projectile's trajectory and maybe even degrade accuracy and precision.

Now, I'm not trying to tell any other person how to shoot their weapon.  But I think I'd restrict my use of this particular device and it's brothers and sisters to just measuring the MV of the rifle and of particular loads.  I'll worry about POI / POA when shooting without the chronograph attached and while shooting for accuracy.

Two different activities with two different goals.

LF

A friend of mine and shooting buddy is concerned about whether rifle ranges will allow the chronograph.  Of course, I'll phone before I go.

But it seems that this device is custom made for rifle ranges, even very busy ones, as if it's used as intended it wouldn't disrupt range operations one bit.

LF

Yep, I looked at the V2 and V3 but they're not at my price point.  So, I decided to try to much less expensive Sporter.  They offer an upgrade option, I hear, if one's not happy with the Sporter.

LF

I am sure you will be happy. Never had any issues with mine.

Well, got it in the mail today.  Will range test my two newly built AR's tomorrow and report back.

Seems pretty flimsy actually.  So, I'll be careful with it.

Best,

LF

Ummm...WOW!!!

I'm really impressed with this inexpensive chronograph (magnetospeed sporter @ $187).  I read the instructions at the range in less than 10 minutes while being pummeled with spent brass from my left and while being rendered deaf by all the nearby muzzle blasts.  I mounted it on my wife's and then my rifle in less than 5 minutes each.  And, I fired 5 rounds each of several loads we intended to use between her rifle and mine and I was DONE!!!.

I read some complaints about this chronograph on the Inet about the "bayonet" coming loose after a few rounds.  Nope.  On the AR15 I had absolutely no problems with the bayonet coming loose and I checked after each round.

Even my wife said, "Wow, that was simple and easy."

And, the range officer who allowed its use told us that he usually didn't allow a chronograph to be set up at the range but on the least busy of days and seasons because they had to shut the range down while the chronograph was set up in front of the firing line and that inconvenienced too many shooters.  But he said that at the range they really liked the Magnetospeed chronos because they didn't have to really pay any attention to their use at all and had no delays for other shooters.

I disassembled it from each rifle in 1 minute for transfer to either my other rifle or the range bag and went home to calculate the ballistic curves for our rifles (see below).  It seemed like a waste of money to have paid the range fee for two rifles and two shooters.  We were there only two relays zeroing her new rifle (it's her B-day) and then using the chronograph.

I simply cannot tell you how simple this chronograph is to use.  It's as simple as slipping on a shooting glove but no shooting glove generates muzzle velocity data.  As Xmas is coming up, some of you without one of those remarkably unreliable or remarkably expensive chronographs might want to give this one a try on your Xmas wish list...or sooner.

BTW, the legend has the letters LD or DW with each load.  LD's my wife's initials and DW are mine, so, they indicate which rifle was used for the shot series.



LF

Can you tell me how you got that graph?  Mine only outputs a .csv file.  Are you just converting that to a graph in excel?

I'm delighted to tell you how.  Briefly, I use the chronograph data along with www.gundata.com's ballistic calculator and input:

1)  B.C data from the bullet manufacturer's site
2)  bullet weight in grains
3)  the range at which I want the ballistic trajectory to give me a long zero (in my case the 300m long zero which is 327 yards).  It calculates the short zero yardage automatically if you give it the long zero.
4) my sight height (2.6")
5) the range I want the graph to cover (600 yards in the one above as I think the max. effective range of the 16" carbine is less than that, maybe 500 yards)
6) the interval between data points (I always choose 1 yard because I want a continuous line on the graph rather than lines connecting points)

The resulting table can be selected easily from the website results and then copied into an Excel spreadsheet.

Then I highlight (select) the yards and the bullet drop (trajectory in inches) columns (they're side by side) and click INSERT.  In Excel 2013 a choice pops up along the top line menu which has the title Recommended Charts.  Within that you find the chart type I use above.

I'm sure earlier versions of Excel would also be useful but the commands may be a bit different.

If you need a little help after you have your data from gundata.com just PM me and we can set up a time where we can link our computers so you can see my screen and I'll process the data into the graph for you so you'll know what to do next time.  I use Mikogo for screen sharing (German and totally secure).

BTW, the graphs look a lot better than what's showing above when they're still in Excel and before you go to the trouble to convert them to a .jpg and upload them to photobucket and then feed them into AR15.com.

Good luck,

LF

I might give it a shot after tomorrow.  Going to grab some new chrono data at the range.

One thing thats weird is the MK262 had the worst ballistics and the M193 had the best according to your graph unless I am reading it wrong.  Seems backwards to me.

Even before I had my chrono and when I used published data from Black Hills and from Old Dominion where I bought the 77 gr. OTM an TMK the MV's were substantially less than the MV of M193.  So, I expected the M193 to shoot flatter over the entire effective range of the AR15 (out to 500 - 600 m).

Plus OTM and TMK bullets are 77 gr. and the M193 is but 55 gr.  As I've recently learned (MV vs. Bullet Weight) the heavier bullet will have less MV than lighter bullets.

Below, I present a graph of MV vs. bullet weight taken from data made available from a Gentleman who posted in the above thread:



So, I fully expected the M193 to have a higher MV in my carbines and to shoot flatter than the MK262 mod 1 OTM or TMK at 77 gr.  So, the ballistic calculations weren't a surprise to me.

Of course, the ballistics charts are hypothetical.  I've finally found a local range (well, if you call within 50 miles local) that allows shooters 300, 400 and 600 yard ranges (provided the shooter "qualfies" with a 10 shot string all in the rings at 300 yards with no flyers).   So, soon I'll be able to verify this.

But I don't think there's much debate as to which ammunition shoots flatter, M193 does.

Perhaps you're confusing terminal ballistics with what I'll call in-flight ballistics.  TMK and OTM do resist wind better at longer ranges due to being heavier and having higher ballistic coefficients, especially TMK.  And, because TMK is not fragmentation dependent or yaw dependent (it mushrooms) it's lethality at longer ranges might be expected to be far superior to M193.  That, at least, is why I'm interested in it as were most of the shooters and poster in the above cited ar15.com thread.

But here's a new development for me.  My wife's carbine is 1X9 and mine is 1X7.  Her carbine can't stabilize 77 gr. bullets, whereas mine can.  Her's and mine can stabilize all bullets up to 69 gr.  And, Black Hills has recently introduced a 69 gr. TMK.  So, if I standardized my family's rifles on the 69 gr. BH TMK we'd never have a problem mixing up green tips and we'd also both shoot a TMK that was a bit flatter.

I'm ordering some 69 gr. TMK from Old Dominion this weekend (200 rds) and we're going to give them a go next weekend.  I'll report back the MVs for those rounds out of my chrono, if you like.

Best,

LF

Thanks for the chart info.  I screwed up this morning and didnt bring my chrono with me, so I wasnt able to get any numbers to try it out.  maybe next time.

Hey, maybe it was a subliminal screw-up.  

It gave you another day at the range, right?

Best,

LF

The reason my range restricts chronographs to "private bay" ranges (25 yards max) is safety and essentially "not pissing off all the other folks on the line while you dink with setting up and tearing down the chrono."  They similarly restrict NFA weapons to those ranges to limit unauthorized access to those weapons.  I need to ask about Magnetospeeds....

Hanging an extra mass on the end of a barrel will shift POI, but it should shift ALL impacts the same amount and in the same direction.  When shooting over a chronograph for both velocity and accuracy, you're not really trying to get all the holes in the X ring, you're trying to get all the holes as close together as possible, and later you can adjust sights accordingly.  That means that, while your groups will not be exactly the same with the Magnetospeed chrono as if you were firing over a traditional chronograph, you should get essentially the same amount of data from using it.  Later, you load up the load with the smallest groups (and usually the most consistent MV), and then zero for that load.  Piece of cake.

Yep, the range folks told me that they were happy to let a Magnetospeed chrono operate on the range, but, not necessarily any other kind which caused them to shut the range down for tinkering.  As you say, they're customer oriented and they get a lot of guff from customers who want to shoot and can't because someone's in front of the firing line.

But the magnetospeed isn't like that.  You just install it and shoot it during the regular relays.  Absolutely no range officer even took particular notice of the thing hanging off the barrel.  I guess they've seen them before at the range even though I've not.

I completely agree.  Chrono-ing and firing for groups are two different activities and should be probably be conducted separately from one another.  At least, that's the way I do it.

Now, if I had a laptop with wifi and could sit at the range after the 15 minutes it took to generate the chrono data to plug it into a ballistics program and then the ballistics data into Excel that would be different.  I'd certainly go on a shoot more to confirm what the ballistics suggested "should be" given the new MV data.

BTW, I think 25 yard private bay for chronos would be a good idea.  My range doesn't seem to have one.

Best,

LF

Ummm, sorry but what's an NFA weapon?

Best,

LF

Machine guns, SBRs, suppressors, etc.

I previously had the V2 version and now have the V3 MagnetoSpeed, and am very happy with the product.  Glad to hear that the Sporter version is available and am not surprised by the positive reviews.  So much easier than setting up a tripod, vanes, screens, trying to aim thru the vanes, etc.  Now I only use the old style chronograph for arrows, pistols, and muzzleloaders...

Topic Moved

OK.  Moved where?

LF

"Slings and Other Accessories."  Not sure if this is the best place for it, but I don't know where else it should go...

Thanks Porter.

Best,

LF