Took the Magnetospeed to the range yesterday

[PMR14]

Had a chance to test out my V2 Magnetospeed yesterday on my 7mm mag Sendaro.

This is a great chronograph and simple to get data. The attachment strap gave me a little trouble, but once I figured it out, it stayed on without any trouble.

I found that my once fired brass gave me a standard deviation of 5 ft/sec. My non fired brass was closer to 17ft/sec. Cool to see the variation.

At 700 yds, it didn't seem to change my point of impact. I consistently hit my target with a nice tight grouping. This is a really nice unit and worked great in 25 degree weather!

 

[KYpatriot]

I am not sure I trust my magnetospeed right now...seems it is giving me slow velocities by about 100fps. It is doing it consistently, but not sure why it has started reading slow all the sudden. FGMM 175gr is reading 2530 for instance out of a 24in 308, not sure what is going on unless federal has changed the load or I have a slow lot of ammo for some reason. ES was in single digits though.

 

[LawnMM]

It wouldn't surprise me if Federal had changed it up a bit. I chrono'd some FGMM 175gr out of a 20" 308, shorter than yours, but it was reading around 2450 or 2430, something along those lines. I was surprised too as I was expected low mid 2500s with the 20" barrel.

 

[PMR14]

KYpatriot,

The first thing that comes to mind is temperature. The powder in your rounds could be affected. But most importantly, you mentioned that all of them were affected similarly. Thats good? Just a thought.

 

[KYpatriot]

Yes it was consistent, still very precise. But slow. Seems that since many agencies use this as duty ammo they would think to tell us if they slowed up the ammo. Temp was 55 deg so I don't think that accounts for much of it, at least in older lots of FGMM I hadn't seen much temp variation, I think in my data book I had seen about a half fps per degree but I'd have to look it up. I don't shoot for groups or at 100 yards much and only crony when checking zero so I don't remember what I recorded for temp variation in the last. I just remember it hasn't been much if a factor, not enough for a 100+ fps drop from before.

My dope for 450 and 650 was working but in truth I was seeing more drop than I expected when I moved back to 885 so maybe the chrony was right. I wasn't pleased with how I was shooting frankly so I don't know what to think just yet. I am going to shoot some groups at range to make sure it isn't me and redo my dope, check my scope, etc basically start from scratch to figure this out. Not ready to blame the ammo, chrony or dope until I am satisfied it wasn't me, because it probably was me. Haven't been shooting as much lately since apparently the weather this winter decided I was no longer below the Mason-Dixon Line.

 

[holderofthehorns]

Strapping stuff onto the end of your barrel will change the barrel harmonics (poi).
I can't imagine this device not doing that.
But, if you rezero with it on your barrel, and leave it there, you should be OK.
Rezero again when you remove it.

Or am I missing something?

 

[maccrazy2]

mine has no noticable change in poi out to 200yds. However my barrel is like a truck axle. i am sure at farther ranges I would see it but close in is not an issue. However I dont need to chrono all day. usally 10 rounds to get an average

 

[KYpatriot]

Just to clarify, I don't shoot long range with the chrony attached. My dope seemed off all the sudden, so I checked zero at a hundred and chronoed and noticed the slower than expected velocities.

I like this chrony, I have one of the first few made.

 

[PMR14]

Holderofthehorns,

I did not see any appreciable difference on poi to 700 yds. I was impressed. I had the unit measuring underneath the bullet and have heard that it can push the bullet in the opposite direction. Maybe subconsciously I knew that and compensated for it, lol.

Overall, it was nice having such a tool for diagnosing reloading variations.

 

[1slow01z71]

Strapping stuff onto the end of your barrel will change the barrel harmonics (poi).
I can't imagine this device not doing that.
But, if you rezero with it on your barrel, and leave it there, you should be OK.
Rezero again when you remove it.

Or am I missing something?

Real world results say youre wrong. I dont get any POI shift with mine. Maybe on a pencil barrel but with the profiles most of us shoot its not a problem.

 

[F4D]

I have the V2 and found that poi is within 1/2 inch at 500 yds. Hard to tell if it is me or the V2. I have tested the V2 with Pellets on up to 338 lapua and only need to adjust the sensitivity for precise readings. Best 350.00 I have spent in a while.

 

[holderofthehorns]

OK to all!!
Sounds good to me. I have yet to fire my 700 .308 26" varmint barrel, so I really don't know. I have been doing TONS of reading getting ready for the springtime (which is almost here). Today, I'm just a wannabe with lots of reading behind him.
Tomorrow, I'll be shooter.

Real world results are what counts. you guys have that, I don't. But soon I will.

The Magnetospeed looks like it could fit into the Range toolbox rather easily.

ME: I've been shooting amateur for 30 years. Never got any better. Then all this 2nd Amendment stuff starts up, and I start to get serious. Now I've read the Fundamentals of Shooting (on this site), ordered and read all the books. Purchased 2 boxes of each major type of .308 ammo, targets are ready, sand bags, etc. Need to see if my rifle likes M118lr better than FGMM. Need to try the other ammo just to see what happens.
I got the blank Range Diary, will document every shot, every dope, every atmospheric and wind and every group.
Why? Because I can. Virgin gun, virgin shooter.

Found an Appleseed about 60 miles from here. Going to visit that.
Found a 400 yard range 10 miles west of here. Going to join that.
Found a bunch of new friends in my area.

This is lots of fun. THANKS to all of you guys for the feedback.