Magneto speed problems in pistol loading

[Monday shooter40]

Using my magneto speed to work up some .40 cal pistol loads. 4 or 5 readings out of 20 will be 3 times the bullet speed.

Say I'm averaging 920 fps , my high reads will be around 2300-2400.

I know my bullets aren't going that fast, but its annoying. Anyone else experience this problem? And what's causing it.

I'm not getting any sensor errors or faults. Just way high velocity readings.

 

[rijndael]

My shooting partner just had similar issues, it was the 9v battery. It was too low. We swapped it for 2 x CR123s.

 

[Goodcat]

Using my magneto speed to work up some .40 cal pistol loads. 4 or 5 readings out of 20 will be 3 times the bullet speed.

Say I'm averaging 920 fps , my high reads will be around 2300-2400.

I know my bullets aren't going that fast, but its annoying. Anyone else experience this problem? And what's causing it.

I'm not getting any sensor errors or faults. Just way high velocity readings.

Try turning your sensitivity down too. Definitely shoot them an email or call, they have great service.

 

[Monday shooter40]

For anyone in the future: I upgraded to CR123 batteries even though my 9v was not but a month or two old. No changes. Unit behaved the same.

My problems occurred at sensitivity level 6. I lowered to sensitivity 2 and it wouldn't even pick up the bullet. Completely blanked 2 rounds.

I raised the sensitivity to 9, and it started giving me sensor errors. 3 shots in a row.

I lowered down to 5. Works like a champ.

I have about 3/8" clearance between the bullet and bayonet.

I've put well over 1000 rifle rounds over my V3 and I have been very satisfied with its performance. my only complaint is that I have built specific mounts for all my rifle chassis and stocks and now for my pistols as well. I do not do the barrel mounting method. Multiple gun tuning sessions can be hectic swapping mounts. I'm not putting the magneto speed down, but for multiple gun applications, I wish I would have went lab radar.

 

[Ray123]

I don't use the Magento Speed for pistols....I use a regular sky screen chronograph for that. Because its hard to get it to fit straight on short barreled autos without a special dust cover attachment.

 

[Hudge76]

I don't use the Magento Speed for pistols....I use a regular sky screen chronograph for that. Because its hard to get it to fit straight on short barreled autos without a special dust cover attachment.

Make you a mount for it. That’s what I did and it seems to work. I drilled a hole in an old Caldwell front bag test mount I had.

 

[Ray123]

Make you a mount for it. That’s what I did and it seems to work. I drilled a hole in an old Caldwell front bag test mount I had.

I have thought about doing a mount of some sort...but I hardly ever chronograph pistols ...just once to see how close a reloading manual is, then I'm done...so for that I just take the old sky screen chronograph and shoot a few pistol rds over it...so it's pretty easy if ya have both types of chronographs, handy...and a bit lazy...or other stuff to do, that seems more important.

 

[Monday shooter40]

I could never get consistent data from my old Caldwell chrono. It never agreed with my V3 on just about everything.

 

[JimSC]

I could never get consistent data from my old Caldwell chrono. It never agreed with my V3 on just about everything.

why would it? A Magnetospeed registers the FPS at muzzle. Opticals will register it 10 - 15 feet from the muzzle. LR's supposedly compute the speed back to the muzzle but in my personal experience it was showing the speed about 12 feet out

example 2800 FPS @ muzzle = 2781 @ 10 Ft and 2771 @ 15 ft using a 308 168 gn and .5 G1 bullet

 

[Monday shooter40]

why would it? A Magnetospeed registers the FPS at muzzle. Opticals will register it 10 - 15 feet from the muzzle. LR's supposedly compute the speed back to the muzzle but in my personal experience it was showing the speed about 12 feet out

example 2800 FPS @ muzzle = 2781 @ 10 Ft and 2771 @ 15 ft using a 308 168 gn and .5 G1 bullet

Im talking 100's of feet per second. Maybe i have a bad apple. But my caldwell is a terrible piece of equipment.

 

[JimSC]

Im talking 100's of feet per second. Maybe i have a bad apple. But my caldwell is a terrible piece of equipment.

biggest problem most have with opticals is they tend to place it too close to muzzle, in particular when using it with pistols and are worried about shooting it.
Also I have no clue how you would use a Magnetospeed with a pistol, maybe you could post a pic of your setup ? I would love to rig something up for mine.

 

[Monday shooter40]

They offer a pic rail attachment for pistols with a pic rail. But naturally, this pistol does not have one.

I just made a L bracket because mounting the magneto speed directly to the frame prevented me from installing the slide. so it had to mount it off to the side.

 

[JimSC]

They offer a pic rail attachment for pistols with a pic rail. But naturally, this pistol does not have one.

I just made a L bracket because mounting the magneto speed directly to the frame prevented me from installing the slide. so it had to mount it off to the side.

Nice Job, beyond what I have the resources to fabricate these days. I really have no need to chrono pistols these days anyway


If I find the need again I will just use my optical set out at 12ft with a target directly behind it and 1/8 wood dowels for the sunshade supports. Back when I was active in pistol competition I shot one of the wire shade supports and knocked the chrono over but did no damage except to the support

 

[El Matador]

why would it? A Magnetospeed registers the FPS at muzzle. Opticals will register it 10 - 15 feet from the muzzle. LR's supposedly compute the speed back to the muzzle but in my personal experience it was showing the speed about 12 feet out

example 2800 FPS @ muzzle = 2781 @ 10 Ft and 2771 @ 15 ft using a 308 168 gn and .5 G1 bullet

Your numbers don't seem very realistic. If you're losing 30 fps for every 5 yards you're doing something wrong. That would be a loss of 600 fps at 100 yards. My calcs are saying you lose 1 fps for every 2 feet in front of the muzzle.

I have a magnetospeed and I had not even considered using it for handguns. Hmmm.

 

[JimSC]

Your numbers don't seem very realistic. If you're losing 30 fps for every 5 yards you're doing something wrong. That would be a loss of 600 fps at 100 yards. My calcs are saying you lose 1 fps for every 2 feet in front of the muzzle.

I have a magnetospeed and I had not even considered using it for handguns. Hmmm.

Good catch, that would be in yards not feet

yds speed
0 2800.0
1 2798.1
2 2796.2
3 2794.3
4 2792.5